Biochemistry of epidermal stem cells.

PubMed

Eckert, Richard L; Adhikary, Gautam; Balasubramanian, Sivaprakasam; Rorke, Ellen A; Vemuri, Mohan C; Boucher, Shayne E; Bickenbach, Jackie R; Kerr, Candace

2013-02-01

The epidermis is an important protective barrier that is essential for maintenance of life. Maintaining this barrier requires continuous cell proliferation and differentiation. Moreover, these processes must be balanced to produce a normal epidermis. The stem cells of the epidermis reside in specific locations in the basal epidermis, hair follicle and sebaceous glands and these cells are responsible for replenishment of this tissue. A great deal of effort has gone into identifying protein epitopes that mark stem cells, in identifying stem cell niche locations, and in understanding how stem cell populations are related. We discuss these studies as they apply to understanding normal epidermal homeostasis and skin cancer. An assortment of stem cell markers have been identified that permit assignment of stem cells to specific regions of the epidermis, and progress has been made in understanding the role of these cells in normal epidermal homeostasis and in conditions of tissue stress. A key finding is the multiple stem cell populations exist in epidermis that give rise to different structures, and that multiple stem cell types may contribute to repair in damaged epidermis. Understanding epidermal stem cell biology is likely to lead to important therapies for treating skin diseases and cancer, and will also contribute to our understanding of stem cells in other systems. This article is part of a Special Issue entitled Biochemistry of Stem Cells. Copyright © 2012 Elsevier B.V. All rights reserved.

Biochemistry of epidermal stem cells☆

PubMed Central

Eckert, Richard L.; Adhikary, Gautam; Balasubramanian, Sivaprakasam; Rorke, Ellen A.; Vemuri, Mohan C.; Boucher, Shayne E.; Bickenbach, Jackie R.; Kerr, Candace

2014-01-01

Background The epidermis is an important protective barrier that is essential for maintenance of life. Maintaining this barrier requires continuous cell proliferation and differentiation. Moreover, these processes must be balanced to produce a normal epidermis. The stem cells of the epidermis reside in specific locations in the basal epidermis, hair follicle and sebaceous glands and these cells are responsible for replenishment of this tissue. Scope of review A great deal of effort has gone into identifying protein epitopes that mark stem cells, in identifying stem cell niche locations, and in understanding how stem cell populations are related. We discuss these studies as they apply to understanding normal epidermal homeostasis and skin cancer. Major conclusions An assortment of stem cell markers have been identified that permit assignment of stem cells to specific regions of the epidermis, and progress has been made in understanding the role of these cells in normal epidermal homeostasis and in conditions of tissue stress. A key finding is the multiple stem cell populations exist in epidermis that give rise to different structures, and that multiple stem cell types may contribute to repair in damaged epidermis. General significance Understanding epidermal stem cell biology is likely to lead to important therapies for treating skin diseases and cancer, and will also contribute to our understanding of stem cells in other systems. This article is part of a Special Issue entitled Biochemistry of Stem Cells. PMID:22820019

Immunohistochemical patterns of ProEx C in vulvar squamous lesions: detection of overexpression of MCM2 and TOP2A.

PubMed

Chen, Hui; Gonzalez, Jorge L; Brennick, Jeoffry B; Liu, Miaoliang; Yan, Shaofeng

2010-09-01

Two major subtypes of vulvar squamous cell carcinomas (SCC) have been described. Basaloid and warty SCC are human papillomavirus-related and associated with classic vulvar intraepithelial neoplasia (VIN). Keratinizing SCC is associated with lichen sclerosus and differentiated VIN, but not with human papillomavirus. This study was undertaken to examine the expression patterns of ProEx C in vulvar SCC and its precursors. We analyzed 22 cases with normal vulvar epidermis, 13 cases of lichen sclerosus, 14 cases of condylomas, 23 cases of high-grade classic VIN, 6 cases of differentiated VIN, 3 cases of verrucous carcinomas, 10 cases of keratinizing SCC, and 8 cases of basaloid and warty SCC. ProEx C targets minichromosome maintenance protein and topoisomerase II alpha protein which are overexpressed in the cell nucleus during aberrant S-phase induction. Marked confluent ProEx C expression is present in high-grade classic VIN with nuclear staining extending into the middle and upper layers of the epidermis. Condylomas show parabasal nuclear immunoreactivity associated with scattered ProEx C-positive nuclei in the more differentiated suprabasilar layers. Invasive SCC shows variable staining patterns. In contrast, ProEx C staining is essentially limited to the basal and parabasal layers in normal epidermis, lichen sclerosus, differentiated VIN, and verrucous carcinoma. Overall, ProEx C is a useful proliferation marker for high-grade VIN analogous to the staining patterns reported in high-grade cervical intraepithelial neoplasia.

Down-regulated PAR-2 is associated in part with interrupted melanosome transfer in pigmented basal cell epithelioma.

PubMed

Sakuraba, Kazuko; Hayashi, Nobukazu; Kawashima, Makoto; Imokawa, Genji

2004-08-01

In pigmented basal cell epithelioma (BCE), there seems to be an abnormal transfer of melanized melanosomes from proliferating melanocytes to basaloid tumor cells. In this study, the interruption of that melanosome transfer was studied with special respect to the altered function of a phagocytic receptor, protease-activated receptor (PAR)-2 in the basaloid tumor cells. We used electron microscopy to clarify the disrupted transfer at the ultrastructural level and then performed immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) to examine the regulation of a phagocytic receptor, PAR-2, expressed on basaloid tumor cells. Electron microscopic analysis revealed that basaloid tumor cells of pigmented BCE have a significantly lower population of melanosomes ( approximately 16.4%) than do normal keratinocytes located in the perilesional normal epidermis ( approximately 91.0%). In contrast, in pigmented seborrheic keratosis (SK), a similarly pigmented epidermal tumor, the distribution of melanin granules does not differ between the lesional ( approximately 93.9%) and the perilesional normal epidermis ( approximately 92.2 %), indicating that interrupted melanosome transfer occurs in BCE but not in all pigmented epithelial tumors. RT-PCR analysis demonstrated that the expression of PAR-2 mRNA transcripts in basaloid cells is significantly decreased in pigmented BCE compared with the perilesional normal epidermis. In contrast, in pigmented SK, where melanosome transfer to basaloid tumor cells is not interrupted, the expression of PAR-2 mRNA transcripts is comparable between the basaloid tumor cells and the perilesional normal epidermis. Immunohistochemistry demonstrated that basaloid cells in pigmented BCE have less immunostaining for PAR-2 than do keratinocytes in the perilesional normal epidermis whereas in pigmented SK, there is no difference in immunostaining for PAR-2 between the basaloid tumor and the perilesional normal epidermis. These findings suggest that the decreased expression of PAR-2 in the basaloid cells is associated in part with the observed interruption of melanosome transfer in pigmented BCE.

Reconstructed human epidermis: A model to study the barrier function

NASA Astrophysics Data System (ADS)

Barbotteau, Y.; Gontier, E.; Barberet, P.; Cappadoro, M.; De Wever, B.; Habchi, C.; Incerti, S.; Mavon, A.; Moretto, P.; Pouthier, T.; Smith, R. W.; Ynsa, M. D.

2005-04-01

The use of in vitro reconstructed human epidermis (RHE) by the cosmetic and pharmaceutical industries is increasing because of its similar physiological mechanisms to native human skin. With the advent of ethic laws on animal experimentation, RHE provides an helpful alternative for the test of formulations. The aim of this study is to check that the RHE mineral status is comparable to that of human native skin by investigating the elemental distributions in the epidermis strata. In addition, possible deleterious effects of the transport on the epidermis ionic content were studied by nuclear microscopy.

Human epidermis is a novel site of phospholipase B expression.

PubMed

Maury, Eric; Prévost, Marie Claude; Nauze, Michel; Redoulès, Daniel; Tarroux, Roger; Charvéron, Marie; Salles, Jean Pierre; Perret, Bertrand; Chap, Hugues; Gassama-Diagne, Ama

2002-07-12

Phospholipase B (PLB) is an enzyme that displays both phospholipase A(2) and lysophospholipase activities. Analysis of human epidermis homogenates indicated the presence of a 97 kDa PLB protein, as well as a phospholipase A(2) activity, both being enriched in the soluble fraction. Immunolabelling and in situ hybridization experiments showed that this enzyme is expressed in the different layers of epidermis with an accumulation at the dermo-epidermis junction. RT-PCR data indicated that PLB is specifically expressed in natural and reconstructed epidermis. By 3'-RACE-PCR and screening of human genome databases, we obtained a 3600 bp cDNA coding for human PLB highly homologous to already described intestinal brush border PLBs. These data led us to conclude that the soluble PLB corresponds to a proteolytic cleavage of the membrane anchored protein. Altogether, our results provide the first characterization of human PLB which should play an important role in epidermal barrier function.

Comparative study of cryogen spray cooling with R-134a and R-404a: implications for laser treatment of dark human skin

NASA Astrophysics Data System (ADS)

Dai, Tianhong; Yaseen, Mohammad A.; Diagaradjane, Parmeswaran; Chang, David W.; Anvari, Bahman

2006-07-01

Cutaneous laser treatment in dark skin patients is challenging due to significant light absorption by the melanin at the basal layer of epidermis, which can result in irreversible nonspecific thermal injury to the epidermis. Cryogen spray cooling (CSC) with R-134a (boiling point ≈ -26.2°C at 1 atm), which is currently used during cutaneous laser treatment, has shown poor efficacy in protecting dark human skin. We investigated the potential of CSC with R-404a (boiling point ≈ -46.5°C at 1 atm), which has a lower boiling point than R-134a, for improved therapeutic outcome in dark human skin at three levels: in vitro (epoxy resin skin phantom), ex vivo (normal dark human skin sample), and in vivo (skin of the rabbit external ear). The skin phantom was used to acquire the surface and internal temperature profiles in response to CSC with R-134a or R-404a at various spurt durations, based upon which CSC-induced heat removal from the skin phantom was estimated using an algorithm that solved a one-dimensional inverse heat conduction problem. CSC with R-404a increased the temperature reductions within the phantom and subsequently the amount of heat removal from the phantom in comparison to that with R-134a. Normal ex vivo Fitzpatrick types V-VI human skin samples were used to investigate the thermal response of dark human skin epidermis to CSC (R-134a or R-404a) at various spurt durations in conjunction with 595-nm pulsed dye laser irradiation at various radiant exposures. Cryogen R-404a increased the threshold radiant exposures for irreversible thermal injury to the epidermis in dark pigmentation skin. No obvious CSC-induced morphological changes to human skin was observed when sprayed with R404-a spurts using durations up to 300 ms. In vivo rabbit ear vasculature was used as a model of cutaneous anomalies to assess the influences of CSC (with R-134a or R-404a) on the photothermolysis of dermal blood vessels. CSC (R-134a or R-404a) with the spurt durations of 100 to 300 ms increased the most superficial depth of thermally damaged dermal blood vessel compared with the sites without CSC, implying possible nonspecific cooling of superficial dermal blood vessels by the cryogen spurts with the settings applied.

Constitutive and inducible expression of SKALP/elafin provides anti-elastase defense in human epithelia.

PubMed Central

Pfundt, R; van Ruissen, F; van Vlijmen-Willems, I M; Alkemade, H A; Zeeuwen, P L; Jap, P H; Dijkman, H; Fransen, J; Croes, H; van Erp, P E; Schalkwijk, J

1996-01-01

Skin-derived antileukoproteinase (SKALP), also known as elafin, is a serine proteinase inhibitor first discovered in keratinocytes from hyperproliferative human epidermis. In addition to the proteinase inhibiting domain which is directed against polymorphonuclear leukocyte (PMN) derived enzymes such as elastase and proteinase 3, SKALP contains multiple transglutaminase (TGase) substrate domains which enable crosslinking to extracellular and cell envelope proteins. Here we show that SKALP is constitutively expressed in several epithelia that are continuously subjected to inflammatory stimuli, such as the oral cavity and the vagina where it co-localizes with type 1 TGase. All epithelia from sterile body cavities are negative for SKALP. In general, stratified squamous epithelia are positive, whereas pseudostratified epithelia, simple/glandular epithelia and normal epidermis are negative. SKALP was found in fetal tissues of the oral cavity from 17 wk gestation onwards where it continued to be expressed up to adult life. Remarkably, in fetal epidermis SKALP was found from week 28 onwards, but was downregulated to undetectable levels in neonatal skin within three months, suggesting a role during pregnancy in feto-maternal interactions or in the early maturation phase of the epidermis. Immunoelectron microscopy revealed the presence of SKALP in secretory vesicles including the lamellar granules. In culture models for epidermal keratinocytes we found that expression of the endogenous SKALP gene provided protection against cell detachment caused by purified elastase or activated PMNs. Addition of exogenous recombinant SKALP fully protected the keratinocytes against PMN-dependent detachment whereas superoxide dismutase and catalase were only marginally effective. These findings strongly suggest that the constitutive expression of SKALP in squamous epithelia, and the inducible expression in epidermis participate in the control of epithelial integrity, by inhibiting PMN derived proteinases. PMID:8823304

Expression of an Exogenous Growth Hormone Gene by Transplantable Human Epidermal Cells

NASA Astrophysics Data System (ADS)

Morgan, Jeffrey R.; Barrandon, Yann; Green, Howard; Mulligan, Richard C.

1987-09-01

Retrovirus-mediated gene transfer was used to introduce a recombinant human growth hormone gene into cultured human keratinocytes. The transduced keratinocytes secreted biologically active growth hormone into the culture medium. When grafted as an epithelial sheet onto athymic mice, these cultured keratinocytes reconstituted an epidermis that was similar in appearance to that resulting from normal cells, but from which human growth hormone could be extracted. Transduced epidermal cells may prove to be a general vehicle for the delivery of gene products by means of grafting.

Protease-Activated Receptor-2 Is Associated with Terminal Differentiation of Epidermis and Eccrine Sweat Glands

PubMed Central

Shin, Yong-Sup; Kim, Hyung Won; Kim, Chang Deok; Kim, Hyun-Woo; Park, Jin Woon; Jung, Sunggyun; Lee, Jeung-Hoon; Ko, Young-Kwon

2015-01-01

Background Protease-activated receptor 2 (PAR-2) participates in various biological activities, including the regulation of epidermal barrier homeostasis, inflammation, pain perception, and melanosome transfer in the skin. Objective To evaluate the basic physiological role of PAR-2 in skin. Methods We investigated PAR-2 expression in human epidermis, skin tumors, and cultured epidermal cells using western blot and immunohistochemical analysis. Additionally, we examined the effect of the PAR-2 agonist, SLIGRL-NH2, on cultured keratinocytes. Results Strong PAR-2 immunoreactivity was observed in the granular layer of normal human skin and the acrosyringium of the eccrine sweat glands. In contrast, weak PAR-2 immunoreactivity was seen in the granular layer of callused skin and in the duct and gland cells of the eccrine sweat glands. Interestingly, PAR-2 immunoreactivity was very weak or absent in the tumor cells of squamous cell carcinoma (SCC) and syringoma. PAR-2 was detected in primary keratinocytes and SV-40T-transformed human epidermal keratinocytes (SV-HEKs), an immortalized keratinocyte cell line, but not in SCC12 cells. SV-HEKs that were fully differentiated following calcium treatment displayed higher PAR-2 expression than undifferentiated SV-HEKs. Treatment of cultured SV-HEKs with PAR-2 agonist increased loricrin and filaggrin expression, a terminal differentiation marker. Conclusion Our data suggest that PAR-2 is associated with terminal differentiation of epidermis and eccrine sweat glands. PMID:26273149

Protease-Activated Receptor-2 Is Associated with Terminal Differentiation of Epidermis and Eccrine Sweat Glands.

PubMed

Shin, Yong-Sup; Kim, Hyung Won; Kim, Chang Deok; Kim, Hyun-Woo; Park, Jin Woon; Jung, Sunggyun; Lee, Jeung-Hoon; Ko, Young-Kwon; Lee, Young Ho

2015-08-01

Protease-activated receptor 2 (PAR-2) participates in various biological activities, including the regulation of epidermal barrier homeostasis, inflammation, pain perception, and melanosome transfer in the skin. To evaluate the basic physiological role of PAR-2 in skin. We investigated PAR-2 expression in human epidermis, skin tumors, and cultured epidermal cells using western blot and immunohistochemical analysis. Additionally, we examined the effect of the PAR-2 agonist, SLIGRL-NH2, on cultured keratinocytes. Strong PAR-2 immunoreactivity was observed in the granular layer of normal human skin and the acrosyringium of the eccrine sweat glands. In contrast, weak PAR-2 immunoreactivity was seen in the granular layer of callused skin and in the duct and gland cells of the eccrine sweat glands. Interestingly, PAR-2 immunoreactivity was very weak or absent in the tumor cells of squamous cell carcinoma (SCC) and syringoma. PAR-2 was detected in primary keratinocytes and SV-40T-transformed human epidermal keratinocytes (SV-HEKs), an immortalized keratinocyte cell line, but not in SCC12 cells. SV-HEKs that were fully differentiated following calcium treatment displayed higher PAR-2 expression than undifferentiated SV-HEKs. Treatment of cultured SV-HEKs with PAR-2 agonist increased loricrin and filaggrin expression, a terminal differentiation marker. Our data suggest that PAR-2 is associated with terminal differentiation of epidermis and eccrine sweat glands.

Human Langerhans cells express E-cadherin.

PubMed

Blauvelt, A; Katz, S I; Udey, M C

1995-02-01

Murine Langerhans cells (LC) synthesize and express E-cadherin, a Ca(++)-dependent homophilic cell adhesion molecule that mediates LC-keratinocyte (KC) binding in vitro. In vivo, E-cadherin expression by LC may promote localization and persistence of LC within the epidermis through LC-KC adhesion. In addition, changes in LC E-cadherin expression or affinity may be an important factor in the egress of LC from the epidermis after exposure to antigen. The aim of the present study was to determine if human LC also express E-cadherin. Suction blister roofs were obtained from normal volunteers and epidermal cell (EC) suspensions were prepared by limited trypsinization in the presence of 1 mM Ca++. EC were then incubated with antibodies to E-cadherin and CD1a or HLA-DR, and examined by two-color analytical flow cytometry or immunofluorescence microscopy. Most (82.9% +/- 7.4% [mean +/- SD], range 67-89%, n = 7) freshly prepared human LC expressed E-cadherin, as did the majority of KC. The amount of E-cadherin (as determined by mean fluorescence intensity) expressed by LC and KC was similar. Trypsin/EDTA treatment of freshly prepared EC abrogated expression of E-cadherin by LC and KC, whereas E-cadherin was not degraded by trypsin in the presence of Ca++. LC expressed lower levels of E-cadherin after 3 d in culture. Thus, human LC, like murine LC, express the homophilic adhesion molecule E-cadherin, which may be important in establishing and maintaining interactions between LC and KC in mammalian epidermis.

[Application of high-frequency ultrasound in dermabrasion of patients with deep partial-thickness burns].

PubMed

Zang, C Y; Cao, Y Q; Xue, W J; Zhao, R; Zhang, M; Zhang, Y H; Feng, Z; Wang, Y B

2017-02-20

Objective: To investigate the application of high-frequency ultrasound in dermabrasion of patients with deep partial-thickness burns. Methods: Twenty-six patients with deep partial-thickness burns conforming to the study criteria were hospitalized in our unit from March 2015 to March 2016. Patients were all performed with dermabrasion. The structure of skin tissue and blood flow signals of uninjured side and wounds before dermabrasion, and those of wounds immediately post dermabrasion and on post dermabrasion day (PDD) 1, 3, 5, 7, 10, 14, and 21 were detected with high-frequency ultrasound, and the percentage of blood flow signals was calculated. According to the results of comparison between percentage of blood flow signals of wounds and that of normal skin before dermabrasion, patients were divided into no significant decrease group (NSD, n =19) and significant decrease group (SD, n =7). Wound healing time of patients in two groups was recorded. Data were processed with analysis of variance of repeated measurement, LSD test, t test and Chi-square test. The correlation between the percentage of blood flow signals of wounds before dermabrasion and wound healing time of 26 patients were analyzed by Spearman correlation analysis. Results: (1) Epidermis of normal skin of patients in two groups before dermabrasion showed continuous smooth linear hyperecho, which was stronger than that of dermis, and boundary of dermis and subcutaneous tissue showed stronger discontinuous linear echo than that of dermis, which gradually transited to subcutaneous tissue. In group NSD, epidermis of wound of patients before dermabrasion showed intermittent rough linear echo, which was weaker than that of normal skin epidermis, and there was no obvious abnormity of boundary between dermis and subcutaneous tissue. Immediately post dermabrasion and on PDD 1, no linear hyperecho of epidermis was observed, showing complete attrition of epidermis, and the echo of dermis and subcutaneous tissue had no obvious change as compared with that before dermabrasion, with flat surface of dermis and partly abraded superficial-dermis but relatively well preserved dermal tissue in whole. The epidermis showed discontinuous linear hyperecho, and epidermis was discontinuously regenerated on PDD 3 and 5. Partial continuous linear hyperecho was detected in the epidermis, showing partial continuous regeneration of epidermis on PDD 7 and 10. The regenerated epidermis was thicker than normal skin epidermis and showed rough linear hyperecho with non-uniform thickness on PDD 14. The regenerated epidermis was thicker than normal skin epidermis and showed rather smooth linear hyperecho with uniform thickness on PDD 21. In group SD, the structure of epidermis and dermis of wound of patients before dermabrasion, immediately post dermabrasion, and on PDD 1 was similar to that in group NSD, but the echo of boundary of dermis and subcutaneous tissue was weakened in different degrees. There was no linear hyperecho of epidermis, showing no epidermis was regenerated on PDD 3 and 5. Intermittent regeneration of epidermis appeared on PDD 7 and 10 with intermittent linear hyperecho. Partial continuous linear hyperecho was detected in the epidermis, showing partial continuous regeneration of epidermis on PDD 14 and 21. (2) The percentages of blood flow signals of wounds of patients in group NSD before dermabrasion, immediately post dermabrasion, and on PDD 1 were (3.1±1.3)%, (6.5±2.0)%, and (5.3±1.9)% respectively, higher than those in group SD [(0.9±1.1)%, (3.5±1.3)%, and (3.6±0.9)% respectively, P <0.05 or P <0.01]. The percentages of blood flow signals of wounds of patients in two groups were similar at the other time points (with P values above 0.05). Compared with the percentage of normal skin in the same group [(3.2±0.7)%], the percentages of blood flow signals of wounds of patients in group NSD were significantly increased immediately post dermabrasion and on PDD 1 (with P values below 0.01) but had no significant change at the other time points (with P values above 0.05). The percentage of blood flow signals of wounds of patients before dermabrasion in group SD was significantly lower than that of normal skin in the same group [(2.8±0.6)%, P <0.01]. The percentage of blood flow signals of wounds of patients in group SD was close to that of normal skin in the same group at each time point post dermabrasion (with P values above 0.05). (3) The wound healing time of patients in group NSD was (16.2±2.5) d, lower than that in group SD [(30.9±2.9) d, t =12.67, P <0.01]. There was obvious negative correlation between the percentage of blood flow signals of wounds before dermabrasion and wound healing time of 26 patients ( r =-0.77, P <0.01). Conclusions: High-frequency ultrasound is a good way to observe the imaging features of wounds in patients with deep partial-thickness burns before and after dermabrasion, and it can provide objective imaging evidence for the performance of dermabrasion in patients with deep partial-thickness burns.

Esterase Activity and Intracellular Localization in Reconstructed Human Epidermal Cultured Skin Models.

PubMed

Tokudome, Yoshihiro; Katayanagi, Mishina; Hashimoto, Fumie

2015-06-01

Reconstructed human epidermal culture skin models have been developed for cosmetic and pharmaceutical research. This study evaluated the total and carboxyl esterase activities (i.e., Km and Vmax , respectively) and localization in two reconstructed human epidermal culture skin models (LabCyte EPI-MODEL [Japan Tissue Engineering] and EpiDerm [MatTek/Kurabo]). The usefulness of the reconstruction cultured epidermis was also verified by comparison with human and rat epidermis. Homogenized epidermal samples were fractioned by centrifugation. p-nitrophenyl acetate and 4-methylumbelliferyl acetate were used as substrates of total esterase and carboxyl esterase, respectively. Total and carboxyl esterase activities were present in the reconstructed human epidermal culture skin models and were localized in the cytosol. Moreover, the activities and localization were the same as those in human and rat epidermis. LabCyte EPI-MODEL and EpiDerm are potentially useful for esterase activity prediction in human epidermis.

Esterase Activity and Intracellular Localization in Reconstructed Human Epidermal Cultured Skin Models

PubMed Central

Katayanagi, Mishina; Hashimoto, Fumie

2015-01-01

Background Reconstructed human epidermal culture skin models have been developed for cosmetic and pharmaceutical research. Objective This study evaluated the total and carboxyl esterase activities (i.e., Km and Vmax, respectively) and localization in two reconstructed human epidermal culture skin models (LabCyte EPI-MODEL [Japan Tissue Engineering] and EpiDerm [MatTek/Kurabo]). The usefulness of the reconstruction cultured epidermis was also verified by comparison with human and rat epidermis. Methods Homogenized epidermal samples were fractioned by centrifugation. p-nitrophenyl acetate and 4-methylumbelliferyl acetate were used as substrates of total esterase and carboxyl esterase, respectively. Results Total and carboxyl esterase activities were present in the reconstructed human epidermal culture skin models and were localized in the cytosol. Moreover, the activities and localization were the same as those in human and rat epidermis. Conclusion LabCyte EPI-MODEL and EpiDerm are potentially useful for esterase activity prediction in human epidermis. PMID:26082583

The receptor tyrosine kinase ERBB4 is expressed in skin keratinocytes and influences epidermal proliferation.

PubMed

Hoesl, Christine; Röhrl, Jennifer M; Schneider, Marlon R; Dahlhoff, Maik

2018-04-01

The epidermal growth factor receptor (EGFR) and associated receptors ERBB2 and ERBB3 are important for skin development and homeostasis. To date, ERBB4 could not be unambiguously identified in the epidermis. The aim of this study was to analyze the ERBB-receptor family with a special focus on ERBB4 in vitro in human keratinocytes and in vivo in human and murine epidermis. We compared the transcript levels of all ERBB-receptors and the seven EGFR-ligands in HaCaT and A431 cells. ERBB-receptor activity was analyzed after epidermal growth factor (EGF) stimulation by Western blot analysis. The location of the receptors was investigated by immunofluorescence in human keratinocytes and skin. Finally, we investigated the function of ERBB4 in the epidermis of skin-specific ERBB4-knockout mice. After EGF stimulation, all ligands were upregulated except for epigen. Expression levels of EGFR were unchanged, but all other ERBB-receptors were down-regulated after EGF stimulation, although all ERBB-receptors were phosphorylated. We detected ERBB4 at mRNA and protein levels in both human epidermal cell lines and in the basal layer of human and murine epidermis. Skin-specific ERBB4-knockout mice revealed a significantly reduced epidermal thickness with a decreased proliferation rate. ERBB4 is expressed in the basal layer of human epidermis and cultured keratinocytes as well as in murine epidermis. Moreover, ERBB4 is phosphorylated in HaCaT cells due to EGF stimulation, and its deletion in murine epidermis affects skin thickness by decreasing proliferation. ERBB4 is expressed in human keratinocytes and plays a role in murine skin homeostasis. Copyright © 2018 Elsevier B.V. All rights reserved.

Epidermal-skin-test 1,000 (EST-1,000)--a new reconstructed epidermis for in vitro skin corrosivity testing.

PubMed

Hoffmann, J; Heisler, E; Karpinski, S; Losse, J; Thomas, D; Siefken, W; Ahr, H-J; Vohr, H-W; Fuchs, H W

2005-10-01

The determination of a possible corrosive or irritative potential of certain products and ingredients is necessary for their classification and labeling requirements. Reconstructed skin as a model system provides fundamental advantages to single cell culture testing and leads to promising results as shown by different validation studies (for review: Fentem, J.H., Botham, P.A., 2002. ECVAM's activities in validating alternative tests for skin corrosion and irritation. ATLA 30(Suppl. 2), 61-67). In this study we introduce our new reconstructed epidermis "Epidermal-Skin-Test" (EST-1,000). This fully grown epidermis consists of proliferating as well as differentiating keratinocytes. EST-1,000 shows a high comparability to normal human skin as shown by histological and immunohistochemical data. Characteristic markers (KI-67, CK 1/10/5/14, transglutaminase, collagen IV, involucrin, beta 1 integrin) can be identified easily. The main focus of this work was to characterize EST-1,000 especially with respect to its barrier function by testing several substances of known corrosive potential. Skin corrosion was detected by the cytotoxic effect of the substances on a reconstructed epidermis after short-term application to the stratum corneum. The effect was determined by standard MTT assay and accompanying histological analysis. Hence EST-1,000 shows a very high predictive potential and closes the gap between animal testing and the established full-thickness model Advanced-Skin-Test 2,000 (AST-2,000) (Noll, M., Merkle, M.-L., Kandsberger, M., Matthes, T., Fuchs, H., Graeve, T., 1999. Reconstructed human skin (AST-2,000) as a tool for pharmaco-toxicology. ATLA 27, 302).

Changes in Transepidermal Water Loss and Skin Hydration according to Expression of Aquaporin-3 in Psoriasis

PubMed Central

Lee, Young; Je, Young-Jin; Lee, Sang-Sin; Li, Zheng Jun; Choi, Dae-Kyoung; Kwon, Yoo-Bin; Sohn, Kyung-Cheol; Im, Myung; Seo, Young Joon

2012-01-01

Background Aquaporins (AQPs) are a family of water transporting proteins present in many mammalian epithelial and endothelial cell types. Among the AQPs, AQP3 is known to be a water/glycerol transporter expressed in human skin. Objective The relationship between the expression level of AQP3 and transpidermal water loss (TEWL) in the lesional and peri-lesional skin of psoriasis-affected patients, and skin hydration in the lesional and peri-lesional skin of psoriasis patients, was investigated. Methods The expression of AQP3 in psoriasis-affected and healthy control skin was determined using immunohistochemical and immunofluroscence staining. TEWL and skin hydration were measured using a Tewameter® TM210 (Courage & Khazaka, Cologne, Germany) and a Corneometer® CM 820 (Courage & Khazaka), respectively. Results AQP3 was mainly expressed in the plasma membrane of stratum corneum and the stratum spinosum in normal epidermis. Unlike the normal epidermis, AQP3 showed decreased expression in the lesional and peri-lesional epidermis of psoriasis. TEWL was increased, and skin hydration was decreased, in the lesional and peri-lesional skin of psoriasis patients, compared with the healthy control sample. Conclusion Although various factors contribute to reduced skin hydration in the lesional and peri-lesional skin of psoriasis, AQP3 appears to be a key factor in the skin dehydration of psoriasis-affected skin. PMID:22577267

In vitro permeation characterization of repellent picaridin and sunscreen oxybenzone.

PubMed

Gu, Xiaochen; Chen, Ting

2009-01-01

Picaridin and oxybenzone are two active ingredients found in repellent and sunscreen preparations, respectively. We performed a series of in vitro diffusion studies to evaluate the transmembrane permeation of picaridin and oxybenzone across human epidermis and poly(dimethylsiloxane) (PDMS) membrane. Permeation of picaridin (PCR) and oxybenzone (OBZ) across human epidermis was suppressed when both active ingredients were used concurrently; increasing concentration of the test compounds further reduced the permeation percentage of picaridin and oxybenzone. While permeation characteristics were correlative between human epidermis and PDMS membrane, permeability of PDMS membrane was significantly larger than that of human epidermis. The findings were different from concurrent use of repellent DEET and sunscreen oxybenzone in which a synergistic permeation enhancement was observed. Further comparative studies are therefore needed to understand permeation mechanisms and interactions between picaridin and oxybenzone.

Keratinocyte differentiation is regulated by the Rho and ROCK signaling pathway.

PubMed

McMullan, Rachel; Lax, Siân; Robertson, Vicki H; Radford, David J; Broad, Simon; Watt, Fiona M; Rowles, Alison; Croft, Daniel R; Olson, Michael F; Hotchin, Neil A

2003-12-16

The epidermis comprises multiple layers of specialized epithelial cells called keratinocytes. As cells are lost from the outermost epidermal layers, they are replaced through terminal differentiation, in which keratinocytes of the basal layer cease proliferating, migrate upwards, and eventually reach the outermost cornified layers. Normal homeostasis of the epidermis requires that the balance between proliferation and differentiation be tightly regulated. The GTP binding protein RhoA plays a fundamental role in the regulation of the actin cytoskeleton and in the adhesion events that are critically important to normal tissue homeostasis. Two central mediators of the signals from RhoA are the ROCK serine/threonine kinases ROCK-I and ROCK-II. We have analyzed ROCK's role in the regulation of epidermal keratinocyte function by using a pharmacological inhibitor and expressing conditionally active or inactive forms of ROCK-II in primary human keratinocytes. We report that blocking ROCK function results in inhibition of keratinocyte terminal differentiation and an increase in cell proliferation. In contrast, activation of ROCK-II in keratinocytes results in cell cycle arrest and an increase in the expression of a number of genes associated with terminal differentiation. Thus, these results indicate that ROCK plays a critical role in regulating the balance between proliferation and differentiation in human keratinocytes.

Ultraviolet A within Sunlight Induces Mutations in the Epidermal Basal Layer of Engineered Human Skin

PubMed Central

Huang, Xiao Xuan; Bernerd, Françoise; Halliday, Gary Mark

2009-01-01

The ultraviolet B (UVB) waveband within sunlight is an important carcinogen; however, UVA is also likely to be involved. By ascribing mutations to being either UVB or UVA induced, we have previously shown that human skin cancers contain similar numbers of UVB- and UVA-induced mutations, and, importantly, the UVA mutations were at the base of the epidermis of the tumors. To determine whether these mutations occurred in response to UV, we exposed engineered human skin (EHS) to UVA, UVB, or a mixture that resembled sunlight, and then detected mutations by both denaturing high-performance liquid chromatography and DNA sequencing. EHS resembles human skin, modeling differential waveband penetration to the basal, dividing keratinocytes. We administered only four low doses of UV exposure. Both UVA and UVB induced p53 mutations in irradiated EHS, suggesting that sunlight doses that are achievable during normal daily activities are mutagenic. UVA- but not UVB-induced mutations predominated in the basal epidermis that contains dividing keratinocytes and are thought to give rise to skin tumors. These studies indicate that both UVA and UVB at physiological doses are mutagenic to keratinocytes in EHS. PMID:19264911

The caspase-1 inhibitor CARD18 is specifically expressed during late differentiation of keratinocytes and its expression is lost in lichen planus.

PubMed

Qin, Haihong; Jin, Jiang; Fischer, Heinz; Mildner, Michael; Gschwandtner, Maria; Mlitz, Veronika; Eckhart, Leopold; Tschachler, Erwin

2017-08-01

CARD18 contains a caspase recruitment domain (CARD) via which it binds to caspase-1 and thereby inhibits caspase-1-mediated activation of the pro-inflammatory cytokine interleukin (IL)-1β. To determine the expression profile and the role of CARD18 during differentiation of keratinocytes and to compare the expression of CARD18 in normal skin and in inflammatory skin diseases. Human keratinocytes were induced to differentiate in monolayer and in 3D skin equivalent cultures. In some experiments, CARD18-specific siRNAs were used to knock down expression of CARD18. CARD18 mRNA levels were determined by quantitative real-time PCR, and CARD18 protein was detected by Western blot and immunofluorescence analyses. In situ expression was analyzed in skin biopsies obtained from healthy donors and patients with psoriasis and lichen planus. CARD18 mRNA was expressed in the epidermis at more than 100-fold higher levels than in any other human tissue. Within the epidermis, CARD18 was specifically expressed in the granular layer. In vitro CARD18 was strongly upregulated at both mRNA and protein levels in keratinocytes undergoing terminal differentiation. In skin equivalent cultures the expression of CARD18 was efficiently suppressed by siRNAs without impairing stratum corneum formation. Epidermal expression of CARD18 was increased after ultraviolet (UV)B irradiation of skin explants. In skin biopsies of patients with psoriasis no consistent regulation of CARD18 expression was observed, however, in lesional epidermis of patients with lichen planus, CARD18 expression was either greatly diminished or entirely absent whereas in non-lesional areas expression was comparable to normal skin. Our results identify CARD18 as a differentiation-associated keratinocyte protein that is altered in abundance by UV stress. Its downregulation in lichen planus indicates a potential role in inflammatory reactions of the epidermis in this disease. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

Choline acetyltransferase-like immunofluorescence in epidermis of human skin.

PubMed

Johansson, O; Wang, L

1993-01-01

Using the indirect immunofluorescence approach the occurrence of choline acetyltransferase-like immunoreactivity in epidermis, except stratum basale, of human skin is described. Immunoreactive cells were also found in hair follicles, sweat gland ducts and sebaceous glands.

Fluorescence dynamics of human epidermis (ex vivo) and skin (in vivo)

NASA Astrophysics Data System (ADS)

Salomatina, Elena V.; Pravdin, Alexander B.

2003-10-01

The temporal behavior of autofluorescence of human skin and epidermis under continuous UV-irradiation has been studied. Fluorescence spectra and kinetic curves of fluorescence intensity have been obtained. The fluorescence intensity recovery after dark period also has been examined. The vitiligo skin and epidermis were used for comparing their spectra with reflectance and fluorescence spectra of healthy skin. The epidermal samples were prepared using surface epidermis stripping technique. It has been concluded that fluorophores being undergone the UVA photobleaching are actually present in epidermal layer, and immediate pigment darkening does contribute, no less than a half of magnitude, to the autofluorescence decrease under continuous UVA irradiation.

Automated epidermis segmentation in histopathological images of human skin stained with hematoxylin and eosin

NASA Astrophysics Data System (ADS)

Kłeczek, Paweł; Dyduch, Grzegorz; Jaworek-Korjakowska, Joanna; Tadeusiewicz, Ryszard

2017-03-01

Background: Epidermis area is an important observation area for the diagnosis of inflammatory skin diseases and skin cancers. Therefore, in order to develop a computer-aided diagnosis system, segmentation of the epidermis area is usually an essential, initial step. This study presents an automated and robust method for epidermis segmentation in whole slide histopathological images of human skin, stained with hematoxylin and eosin. Methods: The proposed method performs epidermis segmentation based on the information about shape and distribution of transparent regions in a slide image and information about distribution and concentration of hematoxylin and eosin stains. It utilizes domain-specific knowledge of morphometric and biochemical properties of skin tissue elements to segment the relevant histopathological structures in human skin. Results: Experimental results on 88 skin histopathological images from three different sources show that the proposed method segments the epidermis with a mean sensitivity of 87 %, a mean specificity of 95% and a mean precision of 57%. It is robust to inter- and intra-image variations in both staining and illumination, and makes no assumptions about the type of skin disorder. The proposed method provides a superior performance compared to the existing techniques.

Overexpression of Wnt5a in mouse epidermis causes no psoriasis phenotype but an impairment of hair follicle anagen development.

PubMed

Zhu, Xuming; Wu, Yumei; Huang, Sixia; Chen, Yingwei; Tao, Yixin; Wang, Yushu; He, Shigang; Shen, Sanbing; Wu, Ji; Guo, Xizhi; Li, Baojie; He, Lin; Ma, Gang

2014-12-01

Increased Wnt5a expression has been observed in psoriatic plaques. However, whether Wnt5a overexpression directly causes psoriasis is unknown. In this study, we generated transgenic (TG) mice with epidermal Wnt5a overexpression under the control of the human K14 promoter. The skin of Wnt5a TG mice was not psoriatic, but characterized with normal proliferation and homeostasis of epidermis. Instead, these TG mice displayed impaired hair follicle transition from telogen to anagen, most likely due to impaired canonical Wnt signalling. These results suggest that increased Wnt5a expression alone is inadequate to induce psoriasis in the skin and possible involvement of Wnt5a in hair follicle cycling. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Small angle scattering polarization biopsy: a comparative analysis of various skin diseases

NASA Astrophysics Data System (ADS)

Zimnyakov, D. A.; Alonova, M. V.; Yermolenko, S. B.; Ivashko, P. V.; Reshetnikova, E. M.; Galkina, E. M.; Utz, S. R.

2013-12-01

An approach to differentiation of the morphological features of normal and pathological human epidermis on the base of statistical analysis of the local polarization states of laser light forward scattered by in-vitro tissue samples is discussed. The eccentricity and the azimuth angle of local polarization ellipses retrieved for various positions of the focused laser beam on the tissue surface, and the coefficient of collimated transmittance are considered as the diagnostic parameters for differentiation. The experimental data obtained with the psoriasis, discoid lupus erythematosus, alopecia, lichen planus, scabies, demodex, and normal skin samples are presented.

Expression of VEGF(xxx)b, the inhibitory isoforms of VEGF, in malignant melanoma.

PubMed

Pritchard-Jones, R O; Dunn, D B A; Qiu, Y; Varey, A H R; Orlando, A; Rigby, H; Harper, S J; Bates, D O

2007-07-16

Malignant melanoma is the most lethal of the skin cancers and the UK incidence is rising faster than that of any other cancer. Angiogenesis - the growth of new vessels from preexisting vasculature - is an absolute requirement for tumour survival and progression beyond a few hundred microns in diameter. We previously described a class of anti-angiogenic isoforms of VEGF, VEGF(xxx)b, that inhibit tumour growth in animal models, and are downregulated in some cancers, but have not been investigated in melanoma. To determine whether VEGF(xxx)b expression was altered in melanoma, PCR and immunohistochemistry of archived human tumour samples were used. In normal epidermis and in a proportion of melanoma samples, VEGF(xxx)b staining was seen. Some melanomas had much weaker staining. Subsequent examination revealed that expression was significantly reduced in primary melanoma samples (both horizontal and vertical growth phases) from patients who subsequently developed tumour metastasis compared with those who did not (analysis of variance (ANOVA) P<0.001 metastatic vs nonmetastatic), irrespective of tumour thickness, while the surrounding epidermis showed no difference in expression. Staining for total VEGF expression showed staining in metastatic and nonmetastatic melanomas, and normal epidermis. An absence of VEGF(xxx)b expression appears to predict metastatic spread in patients with primary melanoma. These results suggest that there is a switch in splicing as part of the metastatic process, from anti-angiogenic to pro-angiogenic VEGF isoforms. This may form part of a wider metastatic splicing phenotype.

A Mechanics Model for Sensors Imperfectly Bonded to the Skin for Determination of the Young's Moduli of Epidermis and Dermis.

PubMed

Yuan, J H; Shi, Y; Pharr, M; Feng, X; Rogers, John A; Huang, Yonggang

2016-08-01

A mechanics model is developed for the encapsulated piezoelectric thin-film actuators/sensors system imperfectly bonded to the human skin to simultaneously determine the Young's moduli of the epidermis and dermis as well as the thickness of epidermis.

Increased matriptase zymogen activation in inflammatory skin disorders

PubMed Central

Chen, Cheng-Jueng; Wu, Bai-Yao; Tsao, Pai-In; Chen, Chi-Yung; Wu, Mei-Hsuan; Chan, Yee Lam E.; Lee, Herng-Sheng; Johnson, Michael D.; Eckert, Richard L.; Chen, Ya-Wen; Chou, Fengpai; Lin, Chen-Yong

2011-01-01

Matriptase, a type 2 transmembrane serine protease, and its inhibitor hepatocyte growth factor activator inhibitor (HAI)-1 are required for normal epidermal barrier function, and matriptase activity is tightly regulated during this process. We therefore hypothesized that this protease system might be deregulated in skin disease. To test this, we examined the level and activation state of matriptase in examples of 23 human skin disorders. We first examined matriptase and HAI-1 protein distribution in normal epidermis. Matriptase was detected at high levels at cell-cell junctions in the basal layer and spinous layers but was present at minimal levels in the granular layer. HAI-1 was distributed in a similar pattern, except that high-level expression was retained in the granular layer. This pattern of expression was retained in most skin disorders. We next examined the distribution of activated matriptase. Although activated matriptase is not detected in normal epidermis, a dramatic increase is seen in keratinocytes at the site of inflammation in 16 different skin diseases. To gain further evidence that activation is associated with inflammatory stimuli, we challenged HaCaT cells with acidic pH or H2O2 and observed matriptase activation. These findings suggest that inflammation-associated reactive oxygen species and tissue acidity may enhance matriptase activation in some skin diseases. PMID:21123732

Imaging-guided two-photon excitation-emission-matrix measurements of human skin tissues

NASA Astrophysics Data System (ADS)

Yu, Yingqiu; Lee, Anthony M. D.; Wang, Hequn; Tang, Shuo; Zhao, Jianhua; Lui, Harvey; Zeng, Haishan

2012-07-01

There are increased interests on using multiphoton imaging and spectroscopy for skin tissue characterization and diagnosis. However, most studies have been done with just a few excitation wavelengths. Our objective is to perform a systematic study of the two-photon fluorescence (TPF) properties of skin fluorophores, normal skin, and diseased skin tissues. A nonlinear excitation-emission-matrix (EEM) spectroscopy system with multiphoton imaging guidance was constructed. A tunable femtosecond laser was used to vary excitation wavelengths from 730 to 920 nm for EEM data acquisition. EEM measurements were performed on excised fresh normal skin tissues, seborrheic keratosis tissue samples, and skin fluorophores including: NADH, FAD, keratin, melanin, collagen, and elastin. We found that in the stratum corneum and upper epidermis of normal skin, the cells have large sizes and the TPF originates from keratin. In the lower epidermis, cells are smaller and TPF is dominated by NADH contributions. In the dermis, TPF is dominated by elastin components. The depth resolved EEM measurements also demonstrated that keratin structure has intruded into the middle sublayers of the epidermal part of the seborrheic keratosis lesion. These results suggest that the imaging guided TPF EEM spectroscopy provides useful information for the development of multiphoton clinical devices for skin disease diagnosis.

Isolating RNA from precursor and mature melanocytes from human vitiligo and normal skin using laser capture microdissection.

PubMed

Goldstein, Nathaniel B; Koster, Maranke I; Hoaglin, Laura G; Wright, Michael J; Robinson, Steven E; Robinson, William A; Roop, Dennis R; Norris, David A; Birlea, Stanca A

2016-10-01

To characterize the gene expression profile of regenerated melanocytes in the narrow band UVB (NBUVB)-treated vitiligo epidermis and their precursors in the hair follicle, we present here a strategy of RNA isolation from in situ melanocytes using human frozen skin. We developed a rapid immunostaining protocol using the NKI-beteb antibody, which labels differentiated and precursor melanocytes, followed by fluorescent laser capture microdissection. This technique enabled the direct isolation, from melanocyte and adjacent keratinocyte populations, of satisfactory quality RNA that was successfully amplified and analysed by qRT-PCR. The melanocyte-specific gene transcripts TYR, DCT, TYRP1 and PMEL were significantly upregulated in our NBUVB-treated melanocyte samples as compared with the keratinocyte samples, while keratinocyte-specific genes (KRT5 and KRT14) were expressed significantly higher in the keratinocyte samples as compared with the melanocyte samples. Furthermore, in both NBUVB-treated vitiligo skin and normal skin, when bulge melanocytes were compared with epidermal melanocytes, we found significantly lower expression of melanocyte-specific genes and significantly higher expression of three melanocytic stem cell genes (SOX9, WIF1 and SFRP1), while ALCAM and ALDH1A1 transcripts did not show significant variation. We found significantly higher expression of melanocyte-specific genes in the epidermis of NBUVB-treated vitiligo, as compared to the normal skin. When comparing bulge melanocyte samples from untreated vitiligo, NBUVB-treated vitiligo and normal skin, we did not find significant differences in the expression of melanocyte-specific genes or melanocytic stem cell genes. These techniques offer valuable opportunities to study melanocytes and their precursors in vitiligo and other pigmentation disorders. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Merkel cell polyomavirus small T antigen initiates Merkel cell carcinoma-like tumor development in mice

PubMed Central

Verhaegen, Monique E.; Mangelberger, Doris; Harms, Paul W.; Eberl, Markus; Wilbert, Dawn M.; Meireles, Julia; Bichakjian, Christopher K.; Saunders, Thomas L.; Wong, Sunny Y.; Dlugosz, Andrzej A.

2017-01-01

Merkel cell carcinoma (MCC) tumor cells express several markers detected in normal Merkel cells, a non-proliferative population of neuroendocrine cells which arise from epidermis. MCCs frequently contain Merkel cell polyomavirus (MCPyV) DNA and express viral transforming antigens, sT and tLT, but the role of these putative oncogenes in MCC development, and this tumor’s cell of origin, are unknown. Using a panel of pre-term transgenic mice, we show that epidermis-targeted co-expression of sT and the cell fate determinant atonal bHLH transcription factor 1 (Atoh1) leads to development of widespread cellular aggregates with histology and marker expression mimicking that of human intraepidermal MCC. The MCC-like tumor phenotype was dependent on the FBXW7-binding domain of sT, but not the sT-PP2A binding domain. Co-expression of MCPyV tLT did not appreciably alter the phenotype driven by either sT or sT combined with Atoh1. MCPyV sT, when co-expressed with Atoh1, is thus sufficient to initiate development of epidermis-derived MCC-like tumors in mice. PMID:28512245

Merkel Cell Polyomavirus Small T Antigen Initiates Merkel Cell Carcinoma-like Tumor Development in Mice.

PubMed

Verhaegen, Monique E; Mangelberger, Doris; Harms, Paul W; Eberl, Markus; Wilbert, Dawn M; Meireles, Julia; Bichakjian, Christopher K; Saunders, Thomas L; Wong, Sunny Y; Dlugosz, Andrzej A

2017-06-15

Merkel cell carcinoma (MCC) tumor cells express several markers detected in normal Merkel cells, a nonproliferative population of neuroendocrine cells that arise from epidermis. MCCs frequently contain Merkel cell polyomavirus (MCPyV) DNA and express viral transforming antigens, sT and tLT, but the role of these putative oncogenes in MCC development, and this tumor's cell of origin, are unknown. Using a panel of preterm transgenic mice, we show that epidermis-targeted coexpression of sT and the cell fate-determinant atonal bHLH transcription factor 1 (ATOH1) leads to development of widespread cellular aggregates, with histology and marker expression mimicking that of human intraepidermal MCC. The MCC-like tumor phenotype was dependent on the FBXW7-binding domain of sT, but not the sT-PP2A binding domain. Coexpression of MCPyV tLT did not appreciably alter the phenotype driven by either sT or sT combined with ATOH1. MCPyV sT, when coexpressed with ATOH1, is thus sufficient to initiate development of epidermis-derived MCC-like tumors in mice. Cancer Res; 77(12); 3151-7. ©2017 AACR . ©2017 American Association for Cancer Research.

Cultivation and grafting of human keratinocytes on a poly(hydroxyethyl methacrylate) support to the wound bed: a clinical study.

PubMed

Dvoránková, B; Smetana, K; Königová, R; Singerová, H; Vacík, J; Jelínková, M; Kapounková, Z; Zahradník, M

1998-01-01

Cultured epithelial sheets on a textile support are used for the treatment of seriously burned patients. In this study we demonstrate a new procedure for the grafting of keratinocytes directly on a polymer cultivation support. This procedure is much easier in comparison with classical techniques, and encouraging results of clinical trials demonstrate the improved healing of the wound bed after the use of this procedure. There is no difference in the cytokeratine pattern (LP-34, cytokeratin-10) of the reconstructed epidermis and normal human skin.

A Mechanics Model for Sensors Imperfectly Bonded to the Skin for Determination of the Young's Moduli of Epidermis and Dermis

PubMed Central

Yuan, J. H.; Shi, Y.; Pharr, M.; Feng, X.; Rogers, John A.; Huang, Yonggang

2016-01-01

A mechanics model is developed for the encapsulated piezoelectric thin-film actuators/sensors system imperfectly bonded to the human skin to simultaneously determine the Young's moduli of the epidermis and dermis as well as the thickness of epidermis. PMID:27330219

Getting under the skin of epidermal morphogenesis.

PubMed

Fuchs, Elaine; Raghavan, Srikala

2002-03-01

At the surface of the skin, the epidermis serves as the armour for the body. Scientists are now closer than ever to understanding how the epidermis accomplishes this extraordinary feat, and is able to survive and replenish itself under the harshest conditions that face any tissue. By combining genetic engineering with cell-biological studies and with human genome data analyses, skin biologists are discovering the mechanisms that underlie the development and differentiation of the epidermis and hair follicles of the skin. This explosion of knowledge paves the way for new discoveries into the genetic bases of human skin disorders and for developing new therapeutics.

Spontaneous squamous cell carcinoma induced by the somatic inactivation of retinoblastoma and Trp53 tumor suppressors.

PubMed

Martínez-Cruz, Ana Belén; Santos, Mirentxu; Lara, M Fernanda; Segrelles, Carmen; Ruiz, Sergio; Moral, Marta; Lorz, Corina; García-Escudero, Ramón; Paramio, Jesús M

2008-02-01

Squamous cell carcinomas (SCC) represent the most aggressive type of nonmelanoma skin cancer. Although little is known about the causal alterations of SCCs, in organ-transplanted patients the E7 and E6 oncogenes of human papillomavirus, targeting the p53- and pRb-dependent pathways, have been widely involved. Here, we report the functional consequences of the simultaneous elimination of Trp53 and retinoblastoma (Rb) genes in epidermis using Cre-loxP system. Loss of p53, but not pRb, produces spontaneous tumor development, indicating that p53 is the predominant tumor suppressor acting in mouse epidermis. Although the simultaneous inactivation of pRb and p53 does not aggravate the phenotype observed in Rb-deficient epidermis in terms of proliferation and/or differentiation, spontaneous SCC development is severely accelerated in doubly deficient mice. The tumors are aggressive and undifferentiated and display a hair follicle origin. Detailed analysis indicates that the acceleration is mediated by premature activation of the epidermal growth factor receptor/Akt pathway, resulting in increased proliferation in normal and dysplastic hair follicles and augmented tumor angiogenesis. The molecular characteristics of this model provide valuable tools to understand epidermal tumor formation and may ultimately contribute to the development of therapies for the treatment of aggressive squamous cancer.

Histopathology of acute human immunodeficiency virus exanthema.

PubMed Central

Balslev, E; Thomsen, H K; Weismann, K

1990-01-01

Acute exanthema occurs in patients who are human immunodeficiency virus (HIV) positive before they become seropositive. The patients have influenza like symptoms and a macular skin rash on the upper trunk. Histopathological investigation of skin punch biopsy specimens from four patients with acute HIV exanthema showed a normal epidermis and a sparse dermal, mainly perivascular, lymphocytic/histiocytic infiltrate around vessels of the superficial plexus. Histopathological changes of the exanthema of acute HIV infection are non-specific and resemble those of other acute viral exanthema, but when both the histopathological features and the clinical picture are suggestive, the clinician should take into consideration the possibility of HIV infection. Images PMID:2332516

Human Keratinocyte Growth and Differentiation on Acellular Porcine Dermal Matrix in relation to Wound Healing Potential

PubMed Central

Zajicek, Robert; Mandys, Vaclav; Mestak, Ondrej; Sevcik, Jan; Königova, Radana; Matouskova, Eva

2012-01-01

A number of implantable biomaterials derived from animal tissues are now used in modern surgery. Xe-Derma is a dry, sterile, acellular porcine dermis. It has a remarkable healing effect on burns and other wounds. Our hypothesis was that the natural biological structure of Xe-Derma plays an important role in keratinocyte proliferation and formation of epidermal architecture in vitro as well as in vivo. The bioactivity of Xe-Derma was studied by a cell culture assay. We analyzed growth and differentiation of human keratinocytes cultured in vitro on Xe-Derma, and we compared the results with formation of neoepidermis in the deep dermal wounds treated with Xe-Derma. Keratinocytes cultured on Xe-Derma submerged in the culture medium achieved confluence in 7–10 days. After lifting the cultures to the air-liquid interface, the keratinocytes were stratified and differentiated within one week, forming an epidermis with basal, spinous, granular, and stratum corneum layers. Immunohistochemical detection of high-molecular weight cytokeratins (HMW CKs), CD29, p63, and involucrin confirmed the similarity of organization and differentiation of the cultured epidermal cells to the normal epidermis. The results suggest that the firm natural structure of Xe-Derma stimulates proliferation and differentiation of human primary keratinocytes and by this way improves wound healing. PMID:22629190

Human keratinocyte growth and differentiation on acellular porcine dermal matrix in relation to wound healing potential.

PubMed

Zajicek, Robert; Mandys, Vaclav; Mestak, Ondrej; Sevcik, Jan; Königova, Radana; Matouskova, Eva

2012-01-01

A number of implantable biomaterials derived from animal tissues are now used in modern surgery. Xe-Derma is a dry, sterile, acellular porcine dermis. It has a remarkable healing effect on burns and other wounds. Our hypothesis was that the natural biological structure of Xe-Derma plays an important role in keratinocyte proliferation and formation of epidermal architecture in vitro as well as in vivo. The bioactivity of Xe-Derma was studied by a cell culture assay. We analyzed growth and differentiation of human keratinocytes cultured in vitro on Xe-Derma, and we compared the results with formation of neoepidermis in the deep dermal wounds treated with Xe-Derma. Keratinocytes cultured on Xe-Derma submerged in the culture medium achieved confluence in 7-10 days. After lifting the cultures to the air-liquid interface, the keratinocytes were stratified and differentiated within one week, forming an epidermis with basal, spinous, granular, and stratum corneum layers. Immunohistochemical detection of high-molecular weight cytokeratins (HMW CKs), CD29, p63, and involucrin confirmed the similarity of organization and differentiation of the cultured epidermal cells to the normal epidermis. The results suggest that the firm natural structure of Xe-Derma stimulates proliferation and differentiation of human primary keratinocytes and by this way improves wound healing.

Expression of drebrin, an actin binding protein, in basal cell carcinoma, trichoblastoma and trichoepithelioma.

PubMed

Mizutani, Yoko; Iwamoto, Ikuko; Kanoh, Hiroyuki; Seishima, Mariko; Nagata, Koh-ichi

2014-06-01

Drebrin, an F-actin binding protein, is known to play important roles in cell migration, synaptogenesis and neural plasticity. Although drebrin was long thought to be specific for neuronal cells, its expression has recently been reported in non-neuronal cells. As for skin-derived cells, drebrin was shown to be enriched at adhering junctions (AJs) in cultured primary keratinocytes and also be highly expressed in basal cell carcinoma (BCC) cells. Since BCC and two types of benign neoplasm, trichoblastoma and trichoepithelioma, are considered to derive from the same origin, follicular germinative cells, it is sometimes difficult to morphologically distinguish BCC from trichoblastoma and trichoepithelioma. In this study, we performed immunohistochemical staining of drebrin in BCC, trichoblastoma and trichoepithelioma, to examine whether drebrin could serve as a biomarker for BCC diagnosis. In western blotting, drebrin was detected highly and moderately in the lysates from a squamous cell carcinoma cell line, DJM-1, and normal human epidermis, respectively. In immunofluorescence analyses, drebrin was colocalized with markers of AJs and tight junctions in DJM-1 cells and detected at cell-cell junction areas of human normal epidermis tissue. We then examined the distribution patterns of drebrin in BCC, trichoblastoma and trichoepithelioma. In BCC tissues, intense and homogeneous drebrin expression was observed mainly at tumor cell-cell boundaries. In contrast, drebrin was stained only weakly and non-homogeneously in trichoblastoma and trichoepthelioma tissue samples. For differential diagnosis of BCC, drebrin may be a novel and useful marker.

Transferrin receptors in human tissues: their distribution and possible clinical relevance.

PubMed

Gatter, K C; Brown, G; Trowbridge, I S; Woolston, R E; Mason, D Y

1983-05-01

The distribution of transferrin receptors (TR) has been studied in a range of normal and malignant tissues using four monoclonal antibodies, BK19.9, B3/25, T56/14 and T58/1. In normal tissues TR was found in a limited number of sites, notably basal epidermis, the endocrine pancreas, hepatocytes, Kupffer cells, testis and pituitary. This restricted pattern of distribution may be relevant to the characteristic pattern of iron deposition in primary haemachromatosis. In contrast to this limited pattern of expression in normal tissue, the receptor was widely distributed in carcinomas, sarcomas and in samples from cases of Hodgkin's disease. This malignancy-associated expression of the receptor may play a role in the anaemia of advanced malignancy by competing with the bone marrow for serum iron.

Transferrin receptors in human tissues: their distribution and possible clinical relevance.

PubMed Central

Gatter, K C; Brown, G; Trowbridge, I S; Woolston, R E; Mason, D Y

1983-01-01

The distribution of transferrin receptors (TR) has been studied in a range of normal and malignant tissues using four monoclonal antibodies, BK19.9, B3/25, T56/14 and T58/1. In normal tissues TR was found in a limited number of sites, notably basal epidermis, the endocrine pancreas, hepatocytes, Kupffer cells, testis and pituitary. This restricted pattern of distribution may be relevant to the characteristic pattern of iron deposition in primary haemachromatosis. In contrast to this limited pattern of expression in normal tissue, the receptor was widely distributed in carcinomas, sarcomas and in samples from cases of Hodgkin's disease. This malignancy-associated expression of the receptor may play a role in the anaemia of advanced malignancy by competing with the bone marrow for serum iron. Images PMID:6302135

Signalling in the epidermis: the E2F cell cycle regulatory pathway in epidermal morphogenesis, regeneration and transformation.

PubMed

Ivanova, Iordanka A; D'Souza, Sudhir J A; Dagnino, Lina

2005-01-01

The epidermis is the outermost layer in the skin, and it is the first line of defence against the environment. The epidermis also provides a barrier against loss of fluids and electrolytes, which is crucial for life. Essential in the maintenance of this tissue is its ability to continually self-renew and regenerate after injury. These two characteristics are critically dependent on the ability of the principal epidermal cell type, the keratinocyte, to proliferate and to respond to differentiation cues. Indeed, the epidermis is a multilayered tissue composed of keratinocyte stem cells and their differentiated progeny. Central for the control of cell proliferation is the E2F transcription factor regulatory network. This signaling network also includes cyclins, cdk, cdk inhibitors and the retinoblastoma (pRb) family of proteins. The biological importance of the E2F/pRb pathway is emphasized by the fact that a majority of human tumours exhibit alterations that disrupt the ability of pRb proteins to inhibit E2F, leading to permanent activation of the latter. Further, E2F is essential for normal epidermal regeneration after injury. Other member of the E2F signaling pathway are also involved in epidermal development and pathophysiology. Thus, whereas the pRb family of proteins is essential for epidermal morphogenesis, abnormal regulation of cyclins and E2F proteins results in tumorgenesis in this tissue. In this review, we discuss the role of each member of this important growth regulatory network in epidermal formation, homeostasis and carcinogenesis.

Signalling In The Epidermis: The E2f Cell Cycle Regulatory Pathway In Epidermal Morphogenesis, Regeneration And Transformation

PubMed Central

2005-01-01

The epidermis is the outermost layer in the skin, and it is the first line of defence against the environment. The epidermis also provides a barrier against loss of fluids and electrolytes, which is crucial for life. Essential in the maintenance of this tissue is its ability to continually self-renew and regenerate after injury. These two characteristics are critically dependent on the ability of the principal epidermal cell type, the keratinocyte, to proliferate and to respond to differentiation cues. Indeed, the epidermis is a multilayered tissue composed of keratinocyte stem cells and their differentiated progeny. Central for the control of cell proliferation is the E2F transcription factor regulatory network. This signaling network also includes cyclins, cdk, cdk inhibitors and the retinoblastoma (pRb) family of proteins. The biological importance of the E2F/pRb pathway is emphasized by the fact that a majority of human tumours exhibit alterations that disrupt the ability of pRb proteins to inhibit E2F, leading to permanent activation of the latter. Further, E2F is essential for normal epidermal regeneration after injury. Other member of the E2F signaling pathway are also involved in epidermal development and pathophysiology. Thus, whereas the pRb family of proteins is essential for epidermal morphogenesis, abnormal regulation of cyclins and E2F proteins results in tumorgenesis in this tissue. In this review, we discuss the role of each member of this important growth regulatory network in epidermal formation, homeostasis and carcinogenesis. PMID:15951853

Automated analysis and classification of melanocytic tumor on skin whole slide images.

PubMed

Xu, Hongming; Lu, Cheng; Berendt, Richard; Jha, Naresh; Mandal, Mrinal

2018-06-01

This paper presents a computer-aided technique for automated analysis and classification of melanocytic tumor on skin whole slide biopsy images. The proposed technique consists of four main modules. First, skin epidermis and dermis regions are segmented by a multi-resolution framework. Next, epidermis analysis is performed, where a set of epidermis features reflecting nuclear morphologies and spatial distributions is computed. In parallel with epidermis analysis, dermis analysis is also performed, where dermal cell nuclei are segmented and a set of textural and cytological features are computed. Finally, the skin melanocytic image is classified into different categories such as melanoma, nevus or normal tissue by using a multi-class support vector machine (mSVM) with extracted epidermis and dermis features. Experimental results on 66 skin whole slide images indicate that the proposed technique achieves more than 95% classification accuracy, which suggests that the technique has the potential to be used for assisting pathologists on skin biopsy image analysis and classification. Copyright © 2018 Elsevier Ltd. All rights reserved.

Human skin penetration and local effects of topical nano zinc oxide after occlusion and barrier impairment.

PubMed

Leite-Silva, V R; Sanchez, W Y; Studier, H; Liu, D C; Mohammed, Y H; Holmes, A M; Ryan, E M; Haridass, I N; Chandrasekaran, N C; Becker, W; Grice, J E; Benson, H A E; Roberts, M S

2016-07-01

Public health concerns continue to exist over the safety of zinc oxide nanoparticles that are commonly used in sunscreen formulations. In this work, we assessed the effects of two conditions which may be encountered in everyday sunscreen use, occlusion and a compromised skin barrier, on the penetration and local toxicity of two topically applied zinc oxide nanoparticle products. Caprylic/capric triglyceride (CCT) suspensions of commercially used zinc oxide nanoparticles, either uncoated or with a silane coating, were applied to intact and barrier impaired skin of volunteers, without and with occlusion for a period of six hours. The exposure time was chosen to simulate normal in-use conditions. Multiphoton tomography with fluorescence lifetime imaging was used to noninvasively assess zinc oxide penetration and cellular metabolic changes that could be indicative of toxicity. We found that zinc oxide nanoparticles did not penetrate into the viable epidermis of intact or barrier impaired skin of volunteers, without or with occlusion. We also observed no apparent toxicity in the viable epidermis below the application sites. These findings were validated by ex vivo human skin studies in which zinc penetration was assessed by multiphoton tomography with fluorescence lifetime imaging as well as Zinpyr-1 staining and toxicity was assessed by MTS assays in zinc oxide treated skin cryosections. In conclusion, applications of zinc oxide nanoparticles under occlusive in-use conditions to volunteers are not associated with any measurable zinc oxide penetration into, or local toxicity in the viable epidermis below the application site. Copyright © 2016 Elsevier B.V. All rights reserved.

Establishment and characterization of a normal melanocyte cell line derived from pig skin.

PubMed

Julé, Sophia; Bossé, Philippe; Egidy, Giorgia; Panthier, Jean-Jacques

2003-08-01

Several minipig strains develop spontaneous malignant melanoma. As a first step toward the analysis of genes involved in the tumoral progression of melanoma in these animal models, we developed culture conditions for pig melanocytes whereby melanocytes from normal epidermis can be isolated directly onto mitotically inactivated keratinocytes in Eagle's minimal essential medium supplemented with fetal calf serum, tetradecanoyl phorbol acetate (TPA) and cholera toxin. We also derived an immortal line of pigmented melanocytes from the epidermis of a healthy Meishan pig. This cell line, designated PigMel, retains differentiation function in culture, dependence on TPA and cholera toxin and a diploid chromosome number. PigMel melanocytes exhibit morphological and molecular characteristics common to normal mammalian skin melanocytes.

Numerical variation of dark cells in normal and chemically induced hyperplastic epidermis with age of animal and efficiency of tumor promoter. [Mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klein-Szanto, A.J.P.; Slaga, T.J.

1981-11-01

The percentage of dark basal keratinocytes was quantitatively assessed in normal epidermis of Sencar mice before and after birth and in adult epidermis after topical application of several compounds of varying promoting efficiency. The percentage of dark keratinocytes reached a maximum at the 19th day of gestation (approx.40%) and fell abruptly after birth (approx.3%). Old animals exhibited a very low number of dark basal cells (0.2%). After topical application of the weak promoters resiniferotoxin, anthralin, ethylphenylpropiolate, and 12-deoxyphorbol-13-2,4,6-decatrienoate, the percentage of dark cells in young adult epidermis did not differ markedly from that in control (acetone-treated) specimens. The strong first-stagemore » promoters 4-O-methyl-12-O-tetradecanoylphorbol-13-acetate and calcium ionophore A 23187, as well as the strong complete promoter 12-deoxyphorbol-13-deoxyphorbol-13-decanoate, induced the appearance of large numbers of dark keratinocytes, in a percentage similar to that seen after 12-O-tetra-decanoylphorbol-13-acetate application (approx.20%). The similarities between the dark keratinocytes seen after topical application of 12-O-tetradecanoylphorbol-13-acetate or other strong promoters and the dark cells observed in the fetal epidermis before the onset of the adult type of epidermal keratinization indicate that potent and/or first stage tumor promoters can be identified by their ability to induce cells resembling fetal-type dedifferentiated keratinocytes.« less

Using FLIM in the study of permeability barrier function of aged and young skin

NASA Astrophysics Data System (ADS)

Xu, P.; Choi, E. H.; Man, M. Q.; Crumrine, D.; Mauro, T.; Elias, P.

2006-02-01

Aged skin commonly is afflicted by inflammatory skin diseases or xerosis/eczema that can be triggered or exacerbated by impaired epidermal permeability barrier homeostasis. It has been previously described a permeability barrier defect in humans of advanced age (> 75 years), which in a murine analog >18 mos, could be attributed to reduced lipid synthesis synthesis. However, the functional abnormality in moderately aged mice is due not to decreased lipid synthesis, but rather to a specific defect in stratum corneum (SC) acidification causing impaired lipid processing processing. Endogenous Na +/H + antiporter (NHE1) level was found declined in moderately aged mouse epidermis. This acidification defect leads to perturbed permeability barrier homeostasis through more than one pathways, we addressed suboptimal activation of the essential, lipid-processing enzyme, β-glucocerebrosidase (BGC) is linked to elevated SC pH. Finally, the importance of the epidermis acidity is shown by the normalization of barrier function after exogenous acidification of moderately aged skin.

Reconstruction of epidermis by grafting of keratinocytes cultured on polymer support--clinical study.

PubMed

Dvoránková, Barbora; Holíková, Zuzana; Vacík, Jirí; Königová, Radana; Kapounková, Zuzana; Michálek, Jirí; Prádn, Martin; Smetana, Karel

2003-03-01

Extensive wound coverage still represents a challenge for contemporary medicine. We demonstrate the results of a clinical trial of the grafting of cultured keratinocytes directly on a polymer cultivation support in the treatment of skin defects in seriously burned patients and in patients with trophic ulcers. Wound closure was evaluated clinically. The morphology and phenotypic pattern of the reconstructed epidermis, including the basal lamina, as well as the presence of Langerhans cells, were evaluated immunocytochemically using a panel of monoclonal antibodies. All layers of the reconstructed epidermis were normally differentiated (cytokeratin immunocytochemistry). The basal lamina contained collagen type IV and laminin. The reconstructed epidermis was extensively colonized by Langerhans cells. The results of the described technology are encouraging, especially in patients after a burn injury. The described procedure is suitable for the treatment of skin defects in clinical practice.

Kinetics of the maintenance of the epidermis

NASA Astrophysics Data System (ADS)

Zhdanov, Vladimir P.; Cho, Nam-Joon

2013-08-01

The epidermis is the outermost layer of skin. It is comprised of keratin-containing cells called keratinocytes. Functionally, the epidermis serves as a physical barrier that can prevent infection and regulate body hydration. Maintenance and repair of the epidermis are important for human health. Mechanistically, these processes occur primarily via proliferation and differentiation of stem cells located in the basal monolayer. These processes are believed to depend on cell-cell communication and spatial constraints but existing kinetic models focus mainly on proliferation and differentiation. To address this issue, we present a mean-field kinetic model that takes these additional factors into account and describes the epidermis at a biosystem level. The corresponding equations operate with the populations of stem cells and differentiated cells in the basal layer. The keratinocytes located above the basal layer are treated at a more coarse-grained level by considering the thickness of the epidermis. The model clarifies the likely role of various negative feedbacks that may control the epidermis and, accordingly, provides insight into the cellular mechanisms underlying complex biological phenomena such as wound healing.

Development of a wide-field fluorescence imaging system for evaluation of wound re-epithelialization

NASA Astrophysics Data System (ADS)

Franco, Walfre; Gutierrez-Herrera, Enoch; Purschke, Martin; Wang, Ying; Tam, Josh; Anderson, R. Rox; Doukas, Apostolos

2013-03-01

Normal skin barrier function depends on having a viable epidermis, an epithelial layer formed by keratinocytes. The transparent epidermis, which is less than a 100 mum thick, is nearly impossible to see. Thus, the clinical evaluation of re-epithelialization is difficult, which hinders selecting appropriate therapy for promoting wound healing. An imaging system was developed to evaluate epithelialization by detecting endogenous fluorescence emissions of cellular proliferation over a wide field of view. A custom-made 295 nm ultraviolet (UV) light source was used for excitation. Detection was done by integrating a near-UV camera with sensitivity down to 300 nm, a 12 mm quartz lens with iris and focus lock for the UV regime, and a fluorescence bandpass filter with 340 nm center wavelength. To demonstrate that changes in fluorescence are related to cellular processes, the epithelialization of a skin substitute was monitored in vitro. The skin substitute or construct was made by embedding microscopic live human skin tissue columns, 1 mm in diameter and spaced 1 mm apart, in acellular porcine dermis. Fluorescence emissions clearly delineate the extent of lateral surface migration of keratinocytes and the total surface covered by the new epithelium. The fluorescence image of new epidermis spatially correlates with the corresponding color image. A simple, user-friendly way of imaging the presence of skin epithelium would improve wound care in civilian burns, ulcers and surgeries.

Feline atopic dermatitis. A model for Langerhans cell participation in disease pathogenesis.

PubMed

Roosje, P J; Whitaker-Menezes, D; Goldschmidt, M H; Moore, P F; Willemse, T; Murphy, G F

1997-10-01

Atopic dermatitis is a disorder characterized by cutaneous exanthemata as a consequence of exaggerated eczematous reactions to topical and systemic allergens. Langerhans cells, expressing CD1a and HLA-DR, and dermal dendritic cells, expressing HLA-DR, are known to be potent antigen-presenting cells and are thought to play an important role in the pathogenesis of atopic dermatitis. The immunophenotype of lesional skin in atopic dermatitis in humans involves increased numbers of CD1a+/MHC class II+ dendritic cells in addition to activated T cells, mast cells, and macrophages. To establish feline skin as a model for the study of human atopic dermatitis, and to elucidate the role of dendritic cells in feline atopic dermatitis, we investigated the presence of CD1a+ cells and MHC class II+ cells in the epidermis and dermis of lesional feline skin and in skin of healthy control animals. Immunohistochemistry revealed that MHC class II+ epidermal dendritic cells were CD1a+ in normal feline skin and significantly increased numbers of CD1a+ cells and MHC class II+ cells were present in the epidermis and dermis of lesional skin. These data provide the first correlative documentation of CD1a expression by feline dendritic cells containing Birbeck granules, and indicate the utility of feline skin in the study of human cutaneous atopy.

Proteomic profiling reveals candidate markers for arsenic-induced skin keratosis.

PubMed

Guo, Zhiling; Hu, Qin; Tian, Jijing; Yan, Li; Jing, Chuanyong; Xie, Heidi Qunhui; Bao, Wenjun; Rice, Robert H; Zhao, Bin; Jiang, Guibin

2016-11-01

Proteomics technology is an attractive biomarker candidate discovery tool that can be applied to study large sets of biological molecules. To identify novel biomarkers and molecular targets in arsenic-induced skin lesions, we have determined the protein profile of arsenic-affected human epidermal stratum corneum by shotgun proteomics. Samples of palm and foot sole from healthy subjects were analyzed, demonstrating similar protein patterns in palm and sole. Samples were collected from the palms of subjects with arsenic keratosis (lesional and adjacent non-lesional samples) and arsenic-exposed subjects without lesions (normal). Samples from non-exposed healthy individuals served as controls. We found that three proteins in arsenic-exposed lesional epidermis were consistently distinguishably expressed from the unaffected epidermis. One of these proteins, the cadherin-like transmembrane glycoprotein, desmoglein 1 (DSG1) was suppressed. Down-regulation of DSG1 may lead to reduced cell-cell adhesion, resulting in abnormal epidermal differentiation. The expression of keratin 6c (KRT6C) and fatty acid binding protein 5 (FABP5) were significantly increased. FABP5 is an intracellular lipid chaperone that plays an essential role in fatty acid metabolism in human skin. This raises a possibility that overexpression of FABP5 may affect the proliferation or differentiation of keratinocytes by altering lipid metabolism. KRT6C is a constituent of the cytoskeleton that maintains epidermal integrity and cohesion. Abnormal expression of KRT6C may affect its structural role in the epidermis. Our findings suggest an important approach for future studies of arsenic-mediated toxicity and skin cancer, where certain proteins may represent useful biomarkers of early diagnoses in high-risk populations and hopefully new treatment targets. Further studies are required to understand the biological role of these markers in skin pathogenesis from arsenic exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

A molecular systems approach to modelling human skin pigmentation: identifying underlying pathways and critical components.

PubMed

Raghunath, Arathi; Sambarey, Awanti; Sharma, Neha; Mahadevan, Usha; Chandra, Nagasuma

2015-04-29

Ultraviolet radiations (UV) serve as an environmental stress for human skin, and result in melanogenesis, with the pigment melanin having protective effects against UV induced damage. This involves a dynamic and complex regulation of various biological processes that results in the expression of melanin in the outer most layers of the epidermis, where it can exert its protective effect. A comprehensive understanding of the underlying cross talk among different signalling molecules and cell types is only possible through a systems perspective. Increasing incidences of both melanoma and non-melanoma skin cancers necessitate the need to better comprehend UV mediated effects on skin pigmentation at a systems level, so as to ultimately evolve knowledge-based strategies for efficient protection and prevention of skin diseases. A network model for UV-mediated skin pigmentation in the epidermis was constructed and subjected to shortest path analysis. Virtual knock-outs were carried out to identify essential signalling components. We describe a network model for UV-mediated skin pigmentation in the epidermis. The model consists of 265 components (nodes) and 429 directed interactions among them, capturing the manner in which one component influences the other and channels information. Through shortest path analysis, we identify novel signalling pathways relevant to pigmentation. Virtual knock-outs or perturbations of specific nodes in the network have led to the identification of alternate modes of signalling as well as enabled determining essential nodes in the process. The model presented provides a comprehensive picture of UV mediated signalling manifesting in human skin pigmentation. A systems perspective helps provide a holistic purview of interconnections and complexity in the processes leading to pigmentation. The model described here is extensive yet amenable to expansion as new data is gathered. Through this study, we provide a list of important proteins essential for pigmentation which can be further explored to better understand normal pigmentation as well as its pathologies including vitiligo and melanoma, and enable therapeutic intervention.

Evaluation of dermal-epidermal skin equivalents ('composite-skin') of human keratinocytes in a collagen-glycosaminoglycan matrix(Integra artificial skin).

PubMed

Kremer, M; Lang, E; Berger, A C

2000-09-01

Integra artificial skin (Integra LifeSciences Corp., Plainsboro, NJ, USA) is a dermal template consisting of bovine collagen, chondroitin-6-sulphate and a silastic membrane manufactured as Integra. This product has gained widespread use in the clinical treatment of third degree burn wounds and full thickness skin defects of different aetiologies. The product was designed to significantly reduce the time needed to achieve final wound closure in the treatment of major burn wounds, to optimise the sparse autologous donor skin resources and to improve the durable mechanical quality of the skin substitute. The clinical procedure requires two stages. The first step creates a self neodermis, the second creates a self epidermis on the neodermis. However, it is desirable to cover major burn wounds early in a single step by a skin substitute consisting of a dermal equivalent seeded in vitro with autologous keratinocytes ('composite-skin') out of which a full thickness skin develops in vivo.The goal of this experimental study was to develop a method to integrate human keratinocytes in homogeneous distribution and depth into Integra Artificial Skin. The seeded cell-matrix composites were grafted onto athymic mice in order to evaluate their potential to reconstitute a human epidermis in vivo. We were able to demonstrate that the inoculated human keratinocytes reproducibly displayed a homogeneous pattern of distribution, adherence, proliferation and confluence. The cell-matrix composites grafted in this model exhibited good wound adherence, complete healing, minor wound contraction and had the potential to reconstitute an elastic, functional and durable human skin. Histologically we were able to show that the inoculated human keratinocytes in vivo colonised the matrix in a histomorphologically characteristic epidermal pattern (keratomorula, keratinocyte bubbling) and developed a persisting, stratified, keratinising epidermis which immunohistologically proved to be of human origin. These experimental results demonstrate the establishment of an effective cell cultivation process which may be suitable for scale-up production of the epidermal component as large-scale composite-skin grafts. When seeded into Integratrade mark and grafted onto the nude mouse a replacement skin with normal functioning dermal-epidermal components was developed. These results encourage the design of a clinical trial to assess the function of this composite graft in man.

Enhanced secretion of TIMP-1 by human hypertrophic scar keratinocytes could contribute to fibrosis.

PubMed

Simon, Franck; Bergeron, Daniele; Larochelle, Sébastien; Lopez-Vallé, Carlos A; Genest, Hervé; Armour, Alexis; Moulin, Véronique J

2012-05-01

Hypertrophic scars are a pathological process characterized by an excessive deposition of extracellular matrix components. Using a tissue-engineered reconstructed human skin (RHS) method, we previously reported that pathological keratinocytes induce formation of a fibrotic dermal matrix. We further investigated keratinocyte action using conditioned media. Results showed that conditioned media induce a similar action on dermal thickness similar to when an epidermis is present. Using a two-dimensional electrophoresis technique, we then compared conditioned media from normal or hypertrophic scar keratinocytes and determined that TIMP-1 was increased in conditioned media from hypertrophic scar keratinocytes. This differential profile was confirmed using ELISA, assaying TIMP-1 presence on media from monolayer cultured keratinocytes and from RHS. The dermal matrix of these RHS was recreated using mesenchymal cells from three different origins (skin, wound and hypertrophic scar). The effect of increased TIMP-1 levels on dermal fibrosis was also validated independently from the mesenchymal cell origin. Immunodetection of TIMP-1 showed that this protein was increased in the epidermis of hypertrophic scar biopsies. The findings of this study represent an important advance in understanding the role of keratinocytes as a direct potent modulator for matrix degradation and scar tissue remodeling, possibly through inactivation of MMPs. Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved.

Targeted inactivation of integrin-linked kinase in hair follicle stem cells reveals an important modulatory role in skin repair after injury.

PubMed

Nakrieko, Kerry-Ann; Rudkouskaya, Alena; Irvine, Timothy S; D'Souza, Sudhir J A; Dagnino, Lina

2011-07-15

Integrin-linked kinase (ILK) is key for normal epidermal morphogenesis, but little is known about its role in hair follicle stem cells and epidermal regeneration. Hair follicle stem cells are important contributors to newly formed epidermis following injury. We inactivated the Ilk gene in the keratin 15--expressing stem cell population of the mouse hair follicle bulge. Loss of ILK expression in these cells resulted in impaired cutaneous wound healing, with substantially decreased wound closure rates. ILK-deficient stem cells produced very few descendants that moved toward the epidermal surface and into the advancing epithelium that covers the wound. Furthermore, those few mutant cells that homed in the regenerated epidermis exhibited a reduced residence time. Paradoxically, ILK-deficient bulge stem cells responded to anagen growth signals and contributed to newly regenerated hair follicles during this phase of hair follicle growth. Thus ILK plays an important modulatory role in the normal contribution of hair follicle stem cell progeny to the regenerating epidermis following injury.

Targeted inactivation of integrin-linked kinase in hair follicle stem cells reveals an important modulatory role in skin repair after injury

PubMed Central

Nakrieko, Kerry-Ann; Rudkouskaya, Alena; Irvine, Timothy S.; D'souza, Sudhir J. A.; Dagnino, Lina

2011-01-01

Integrin-linked kinase (ILK) is key for normal epidermal morphogenesis, but little is known about its role in hair follicle stem cells and epidermal regeneration. Hair follicle stem cells are important contributors to newly formed epidermis following injury. We inactivated the Ilk gene in the keratin 15–expressing stem cell population of the mouse hair follicle bulge. Loss of ILK expression in these cells resulted in impaired cutaneous wound healing, with substantially decreased wound closure rates. ILK-deficient stem cells produced very few descendants that moved toward the epidermal surface and into the advancing epithelium that covers the wound. Furthermore, those few mutant cells that homed in the regenerated epidermis exhibited a reduced residence time. Paradoxically, ILK-deficient bulge stem cells responded to anagen growth signals and contributed to newly regenerated hair follicles during this phase of hair follicle growth. Thus ILK plays an important modulatory role in the normal contribution of hair follicle stem cell progeny to the regenerating epidermis following injury. PMID:21593206

Keratinocytes propagated in serum-free, feeder-free culture conditions fail to form stratified epidermis in a reconstituted skin model.

PubMed

Lamb, Rebecca; Ambler, Carrie A

2013-01-01

Primary human epidermal stem cells isolated from skin tissues and subsequently expanded in tissue culture are used for human therapeutic use to reconstitute skin on patients and to generate artificial skin in culture for academic and commercial research. Classically, epidermal cells, known as keratinocytes, required fibroblast feeder support and serum-containing media for serial propagation. In alignment with global efforts to remove potential animal contaminants, many serum-free, feeder-free culture methods have been developed that support derivation and growth of these cells in 2-dimensional culture. Here we show that keratinocytes grown continually in serum-free and feeder-free conditions were unable to form into a stratified, mature epidermis in a skin equivalent model. This is not due to loss of cell potential as keratinocytes propagated in serum-free, feeder-free conditions retain their ability to form stratified epidermis when re-introduced to classic serum-containing media. Extracellular calcium supplementation failed to improve epidermis development. In contrast, the addition of serum to commercial, growth media developed for serum-free expansion of keratinocytes facilitated 3-dimensional stratification in our skin equivalent model. Moreover, the addition of heat-inactivated serum improved the epidermis structure and thickness, suggesting that serum contains factors that both aid and inhibit stratification.

Keratinocytes Propagated in Serum-Free, Feeder-Free Culture Conditions Fail to Form Stratified Epidermis in a Reconstituted Skin Model

PubMed Central

Lamb, Rebecca; Ambler, Carrie A.

2013-01-01

Primary human epidermal stem cells isolated from skin tissues and subsequently expanded in tissue culture are used for human therapeutic use to reconstitute skin on patients and to generate artificial skin in culture for academic and commercial research. Classically, epidermal cells, known as keratinocytes, required fibroblast feeder support and serum-containing media for serial propagation. In alignment with global efforts to remove potential animal contaminants, many serum-free, feeder-free culture methods have been developed that support derivation and growth of these cells in 2-dimensional culture. Here we show that keratinocytes grown continually in serum-free and feeder-free conditions were unable to form into a stratified, mature epidermis in a skin equivalent model. This is not due to loss of cell potential as keratinocytes propagated in serum-free, feeder-free conditions retain their ability to form stratified epidermis when re-introduced to classic serum-containing media. Extracellular calcium supplementation failed to improve epidermis development. In contrast, the addition of serum to commercial, growth media developed for serum-free expansion of keratinocytes facilitated 3-dimensional stratification in our skin equivalent model. Moreover, the addition of heat-inactivated serum improved the epidermis structure and thickness, suggesting that serum contains factors that both aid and inhibit stratification. PMID:23326335

Stomatal responses to flooding of the intercellular air spaces suggest a vapor-phase signal between the mesophyll and the guard cells.

PubMed

Sibbernsen, Erik; Mott, Keith A

2010-07-01

Flooding the intercellular air spaces of leaves with water was shown to cause rapid closure of stomata in Tradescantia pallida, Lactuca serriola, Helianthus annuus, and Oenothera caespitosa. The response occurred when water was injected into the intercellular spaces, vacuum infiltrated into the intercellular spaces, or forced into the intercellular spaces by pressurizing the xylem. Injecting 50 mm KCl or silicone oil into the intercellular spaces also caused stomata to close, but the response was slower than with distilled water. Epidermis-mesophyll grafts for T. pallida were created by placing the epidermis of one leaf onto the exposed mesophyll of another leaf. Stomata in these grafts opened under light but closed rapidly when water was allowed to wick between epidermis and the mesophyll. When epidermis-mesophyll grafts were constructed with a thin hydrophobic filter between the mesophyll and epidermis stomata responded normally to light and CO(2). These data, when taken together, suggest that the effect of water on stomata is caused partly by dilution of K(+) in the guard cell and partly by the existence of a vapor-phase signal that originates in the mesophyll and causes stomata to open in the light.

STUDIES ON THE CONSERVATION OF EPIDERMAL SPECIFICITIES OF SKIN AND CERTAIN MUCOSAS IN ADULT MAMMALS

PubMed Central

Billingham, R. E.; Silvers, Willys K.

1967-01-01

To determine whether the factor(s) responsible for the conservation of epidermal specificities in adult guinea pigs and hamsters resides in the germinal layer of the epidermis or in the dermis, thin grafts of skin, possessing qualitatively distinct regional characteristics, were separated into their superficial epidermal and dermal components with the aid of trypsin. Dermis of one type was combined with epidermis of another to produce "recombinant" grafts which were then transplanted to small, full thickness cutaneous sites on the thorax of geneticaily compatible hosts. A variant of this procedure involved transplanting sheets of superficial epidermis of various types to shallow split thickness recipient areas in the skin of the thorax. All grafts were maintained for 100 days before they were excised and examined histologically. The results indicate that, whereas the dermis determines the kind of epidermis produced in recombinant grafts involving the ear, the sole of the foot, and the trunk, this is not the case in recombinants which include tongue, esophageal, or cheek pouch epithelia. The one exception to this occurred when tongue or esophagus epithelia were transplanted to split thickness beds in trunk skin. Here they appeared to produce an epidermis characteristic of their new location. It is believed that this exception is probably due to the fact that the native follicular epidermis present in trunk dermis made such a substantial contribution to the new superficial epidermis that it behaved overtly as body skin epidermis. Taken together, these results suggest that basal layer cells of the superficial epidermis of sole of foot skin, ear skin, and the hair-bearing skin of the general integument behave as if they are equipotential, and that in adult life maintenance of these particular epidermal specificities is the outcome of persistent specific inductive stimuli from the underlying dermis. The results of subsidiary experiments are reported which indicate that the epithelial component of mammary gland tissue is also pluripotential, being capable of producing, under appropriate conditions, a normal-looking, fully stratified superficial epidermis. PMID:5334545

Microbiome dynamics of human epidermis following skin barrier disruption

PubMed Central

2012-01-01

Background Recent advances in sequencing technologies have enabled metagenomic analyses of many human body sites. Several studies have catalogued the composition of bacterial communities of the surface of human skin, mostly under static conditions in healthy volunteers. Skin injury will disturb the cutaneous homeostasis of the host tissue and its commensal microbiota, but the dynamics of this process have not been studied before. Here we analyzed the microbiota of the surface layer and the deeper layers of the stratum corneum of normal skin, and we investigated the dynamics of recolonization of skin microbiota following skin barrier disruption by tape stripping as a model of superficial injury. Results We observed gender differences in microbiota composition and showed that bacteria are not uniformly distributed in the stratum corneum. Phylogenetic distance analysis was employed to follow microbiota development during recolonization of injured skin. Surprisingly, the developing neo-microbiome at day 14 was more similar to that of the deeper stratum corneum layers than to the initial surface microbiome. In addition, we also observed variation in the host response towards superficial injury as assessed by the induction of antimicrobial protein expression in epidermal keratinocytes. Conclusions We suggest that the microbiome of the deeper layers, rather than that of the superficial skin layer, may be regarded as the host indigenous microbiome. Characterization of the skin microbiome under dynamic conditions, and the ensuing response of the microbial community and host tissue, will shed further light on the complex interaction between resident bacteria and epidermis. PMID:23153041

Human and mouse eLOX3 have distinct substrate specificities: implications for their linkage with lipoxygenases in skin

PubMed Central

Yu, Zheyong; Schneider, Claus; Boeglin, William E.; Brash, Alan R.

2008-01-01

Genetic and biochemical evidence suggests a functional link between human 12R-lipoxygenase (12R-LOX) and epidermal lipoxygenase-3 (eLOX3) in normal differentiation of the epidermis; LOX-derived fatty acid hydroperoxide is isomerized by the atypical eLOX3 into a specific epoxyalcohol that is a potential mediator in the pathway. Mouse epidermis expresses a different complement of LOX enzymes, and therefore this metabolic linkage could differ. To test this concept, we compared the substrate specificities of recombinant mouse and human eLOX3 toward sixteen hydroperoxy stereoisomers of arachidonic and linoleic acids. Both enzymes metabolized R-hydroperoxides 2–3 times faster than the corresponding S enantiomers. Whereas 12R-hydroperoxyeicosatetraenoic acid (12R-HPETE) is the best substrate for human eLOX3 (2.4 sec−1; at 30 µM substrate), mouse eLOX3 shows the highest turnover with 8R-HPETE (2.9 sec−1) followed by 8S-HPETE (1.3 sec−1). Novel product structures were characterized from reactions of mouse eLOX3 with 5S-, 8R-, and 8S-HPETEs. 8S-HPETE is converted specifically to a single epoxyalcohol, identified as 10R-hydroxy-8S,9S-epoxyeicosa-5Z,11Z,14Z-trienoic acid. The substrate preference of mouse eLOX3 and the unique occurrence of an 8S-LOX enzyme in mouse skin point to a potential LOX pathway for the production of epoxyalcohol in murine epidermal differentiation. PMID:17045234

H{sup +}/peptide transporter (PEPT2) is expressed in human epidermal keratinocytes and is involved in skin oligopeptide transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kudo, Michiko; Katayoshi, Takeshi; Kobayashi-Nakamura, Kumiko

Peptide transporter 2 (PEPT2) is a member of the proton-coupled oligopeptide transporter family, which mediates the cellular uptake of oligopeptides and peptide-like drugs. Although PEPT2 is expressed in many tissues, its expression in epidermal keratinocytes remains unclear. We investigated PEPT2 expression profile and functional activity in keratinocytes. We confirmed PEPT2 mRNA expression in three keratinocyte lines (normal human epidermal keratinocytes (NHEKs), immortalized keratinocytes, and malignant keratinocytes) by reverse transcription-polymerase chain reaction (RT-PCR) and quantitative real-time RT-PCR. In contrast to PEPT1, PEPT2 expression in the three keratinocytes was similar or higher than that in HepG2 cells, used as PEPT2-positive cells. Immunolocalizationmore » analysis using human skin showed epidermal PEPT2 localization. We studied keratinocyte transport function by measuring the oligopeptide content using liquid chromatography/tandem mass spectrometry. Glycylsarcosine uptake in NHEKs was pH-dependent, suggesting that keratinocytes could absorb small peptides in the presence of an inward H{sup +} gradient. We also performed a skin-permeability test of several oligopeptides using skin substitute, suggesting that di- and tripeptides pass actively through the epidermis. In conclusion, PEPT2 is expressed in keratinocytes and involved in skin oligopeptide uptake. -- Highlights: •PEPT2 is expressed in keratinocytes, which are more common than other skin cells. •Immunolocalization analysis using human skin revealed epidermal PEPT2 localization. •Keratinocytes could absorb small peptides in the presence of an inward H{sup +} gradient. •Di- and tripeptide pass actively through the epidermis.« less

Expression profiles of phases 1 and 2 metabolizing enzymes in human skin and the reconstructed skin models Episkin and full thickness model from Episkin.

PubMed

Luu-The, Van; Duche, Daniel; Ferraris, Corinne; Meunier, Jean-Roch; Leclaire, Jacques; Labrie, Fernand

2009-09-01

Episkin and full thickness model from Episkin (FTM) are human skin models obtained from in vitro growth of keratinocytes into the five typical layers of the epidermis. FTM is a full thickness reconstructed skin model that also contains fibroblasts seeded in a collagen matrix. To assess whether enzymes involved in chemical detoxification are expressed in Episkin and FTM and how their levels compare with the human epidermis, dermis and total skin. Quantification of the mRNA expression levels of phases 1 and 2 metabolizing enzymes in cultured Episkin and FTM and human epidermis, dermis and total skin using Realtime PCR. The data show that the expression profiles of 61 phases 1 and 2 metabolizing enzymes in Episkin, FTM and epidermis are generally similar, with some exceptions. Cytochrome P450-dependent enzymes and flavin monooxygenases are expressed at low levels, while phase 2 metabolizing enzymes are expressed at much higher levels, especially, glutathione-S-transferase P1 (GSTP1) catechol-O-methyl transferase (COMT), steroid sulfotransferase (SULT2B1b), and N-acetyl transferase (NAT5). The present study also identifies the presence of many enzymes involved in cholesterol, arachidonic acid, leukotriene, prostaglandin, eicosatrienoic acids, and vitamin D3 metabolisms. The present data strongly suggest that Episkin and FTM represent reliable and valuable in vitro human skin models for studying the function of phases 1 and 2 metabolizing enzymes in xenobiotic metabolisms. They could be used to replace invasive methods or laboratory animals for skin experiments.

Stomatal Responses to Flooding of the Intercellular Air Spaces Suggest a Vapor-Phase Signal Between the Mesophyll and the Guard Cells1[OA

PubMed Central

Sibbernsen, Erik; Mott, Keith A.

2010-01-01

Flooding the intercellular air spaces of leaves with water was shown to cause rapid closure of stomata in Tradescantia pallida, Lactuca serriola, Helianthus annuus, and Oenothera caespitosa. The response occurred when water was injected into the intercellular spaces, vacuum infiltrated into the intercellular spaces, or forced into the intercellular spaces by pressurizing the xylem. Injecting 50 mm KCl or silicone oil into the intercellular spaces also caused stomata to close, but the response was slower than with distilled water. Epidermis-mesophyll grafts for T. pallida were created by placing the epidermis of one leaf onto the exposed mesophyll of another leaf. Stomata in these grafts opened under light but closed rapidly when water was allowed to wick between epidermis and the mesophyll. When epidermis-mesophyll grafts were constructed with a thin hydrophobic filter between the mesophyll and epidermis stomata responded normally to light and CO2. These data, when taken together, suggest that the effect of water on stomata is caused partly by dilution of K+ in the guard cell and partly by the existence of a vapor-phase signal that originates in the mesophyll and causes stomata to open in the light. PMID:20472750

Defects in antioxidant defense and calcium transport in the epidermis of xeroderma pigmentosum patients.

PubMed

Schallreuter, K U; Pittelkow, M R; Wood, J M

1991-01-01

A comparative study of the antioxidant enzymes superoxide dismutase, catalase, glutathione reductase and thioredoxin reductase was undertaken in two families with xeroderma pigmentosum (XP) and in healthy controls of corresponding skin phototypes. Epidermal blister roofs obtained from the XP patients revealed significant decreases in catalase, thioredoxin reductase, and superoxide dismutase, but glutathione reductase was unaffected. In addition, keratinocytes established from XP patients contained a significantly higher than normal intracellular calcium concentration compared with control cells from a corresponding skin type. Keratinocytes established from an XP obligate heterozygote revealed intermediate levels of calcium between XP homozygotes and controls. Previously high intracellular calcium has been shown to compromise the redox status of keratinocytes by allosteric inhibition of the thioredoxin reductase/thioredoxin electron transfer system. In XP homozygous keratinocytes from sun-exposed epidermis, the intracellular concentration of reduced thioredoxin was decreased to 50% compared with these cells from unexposed skin. Taken together, the results from this study indicate that the epidermis in XP patients lacks effective defense against free radicals and peroxides. In addition to the well-established defect in the normal rates of unscheduled DNA repair, these findings provide an even better explanation for the multiple cutaneous neoplasms in these patients.

The organization of human epidermis: functional epidermal units and phi proportionality.

PubMed

Hoath, Steven B; Leahy, D G

2003-12-01

The concept that mammalian epidermis is structurally organized into functional epidermal units has been proposed on the basis of stratum corneum (SC) architecture, proliferation kinetics, melanocyte:keratinocyte ratios (1:36), and, more recently, Langerhans cell: epidermal cell ratios (1:53). This article examines the concept of functional epidermal units in human skin in which the maintenance of phi (1.618034) proportionality provides a central organizing principle. The following empirical measurements were used: 75,346 nucleated epidermal cells per mm2, 1394 Langerhans cells per mm2, 1999 melanocytes per mm2, 16 (SC) layers, 900-microm2 corneocyte surface area, 17,778 corneocytes per mm2, 14-d (SC) turnover time, and 93,124 per mm2 total epidermal cells. Given these empirical data: (1) the number of corneocytes is a mean proportional between the sum of the Langerhans cell + melanocyte populations and the number of epidermal cells, 3393/17,778-17,778/93,124; (2) the ratio of nucleated epidermal cells over corneocytes is phi proportional, 75,346/17,778 approximately phi3; (3) assuming similar 14-d turnover times for the (SC) and Malpighian epidermis, the number of corneocytes results from subtraction of a cellular fraction equal to approximately 2/phi2 x the number of living cells, 75,436 - (2/phi2 x 75,346) approximately 17,778; and (4) if total epidermal turnover time equals (SC) turnover time x the ratio of living/dead cells, then compartmental turnover times are unequal (14 d for (SC) to 45.3 d for nucleated epidermis approximately 1/2phi) and cellular replacement rates are 52.9 corneocytes/69.3 keratinocytes per mm2 per h approximately 2/phi2. These empirically derived equivalences provide logicomathematical support for the presence of functional epidermal units in human skin. Validation of a phi proportional unit architecture in human epidermis will be important for tissue engineering of skin and the design of instruments for skin measurement.

In Vitro Drug Transfer Due to Drug Retention in Human Epidermis Pretreated with Application of Marketed Estradiol Transdermal Systems.

PubMed

Krishnaiah, Yellela S R; Pavurala, Naresh; Yang, Yang; Manda, Prashanth; Katragadda, Usha; Yang, Yongsheng; Shah, Rakhi; Fang, Guodong; Khan, Mansoor A

2017-08-01

Study objective was to assess skin-to-skin drug transfer potential that may occur due to drug retention in human epidermis (DRE) pretreated with application of estradiol transdermal drug delivery systems (TDDS) and other estradiol transdermal dosage forms (gels and sprays). TDDS (products-A, B, and C) with varying formulation design and composition, and other estradiol transdermal products (gel and spray) were applied to heat separated human epidermis (HSE) and subjected to in vitro drug permeation study. Amounts of DRE were quantified after 24 h. The DRE with product-B was significantly (P < 0.001) higher than that with product-C, product-A, gel, and spray. However, products-A and C, gel, and spray showed almost the same (P > 0.05) amounts of DRE. A separate in vitro permeation study was carried out to determine amounts of drug transferred from drug-retaining epidermis to untreated HSE. The amounts of drug transferred, due to DRE after 8 h, with product-C were significantly (P < 0.001) higher than those with products-A and B, gel, and spray. The in vitro study results indicate a high potential of skin-to-skin drug transfer due to the DRE after labeled period of using estradiol TDDS, though the clinical relevance of these findings is yet to be determined.

Considerations in the improvement of human epidermal keratinocyte culture in vitro.

PubMed

Kaviani, Maryam; Geramizadeh, Bita; Rahsaz, Marjan; Marzban, Saeed

2015-04-01

Large-scale expansion of epidermal keratinocytes is essential in the application of these cells for severe burn treatment in patients. Therefore, this study was designed to evaluate various conditions in the expansion of human epidermal keratinocytes. The epidermis was separated from the dermis of skin samples using dispase. The epidermis was trypsinized for keratinocyte isolation. Keratinocytes were cultured in various conditions, with or without a human dermal fibroblast feeder layer, mitomycin C treatment, and different culture media. Our results suggest that keratinocytes cultured on a human dermal fibroblast feeder layer were grown for several passages. Extensive deformation and rapid deterioration were observed in the cultured cells without a feeder layer and in serum-free medium. Human dermal fibroblasts treated with mitomycin C can provide optimal conditions for proliferation of keratinocytes.

Discrimination between basal cell carcinoma and hair follicles in skin tissue sections by Raman micro-spectroscopy

NASA Astrophysics Data System (ADS)

Larraona-Puy, M.; Ghita, A.; Zoladek, A.; Perkins, W.; Varma, S.; Leach, I. H.; Koloydenko, A. A.; Williams, H.; Notingher, I.

2011-05-01

Skin cancer is the most common human malignancy and basal cell carcinoma (BCC) represents approximately 80% of the non-melanoma cases. Current methods of treatment require histopathological evaluation of the tissues by qualified personnel. However, this method is subjective and in some cases BCC can be confused with other structures in healthy skin, including hair follicles. In this preliminary study, we investigated the potential of Raman micro-spectroscopy (RMS) to discriminate between hair follicles and BCC in skin tissue sections excised during Mohs micrographic surgery (MMS). Imaging and diagnosis of skin sections was automatically generated using ' a priori'-built spectral model based on LDA. This model had 90 ± 9% sensitivity and 85 ± 9% specificity for discrimination of BCC from dermis and epidermis. The model used selected Raman bands corresponding to the largest spectral differences between the Raman spectra of BCC and the normal skin regions, associated mainly with nucleic acids and collagen type I. Raman spectra corresponding to the epidermis regions of the hair follicles were found to be closer to those of healthy epidermis rather than BCC. Comparison between Raman spectral images and the gold standard haematoxylin and eosin (H&E) histopathology diagnosis showed good agreement. Some hair follicle regions were misclassified as BCC; regions corresponded mainly to the outermost layer of hair follicle (basal cells) which are expected to have higher nucleic acid concentration. This preliminary study shows the ability of RMS to distinguish between BCC and other tissue structures associated to healthy skin which can be confused with BCC due to their similar morphology.

Interleukin-33 is expressed in the lesional epidermis in herpes virus infection but not in verruca vulgaris.

PubMed

Jin, Meijuan; Komine, Mayumi; Tsuda, Hidetoshi; Oshio, Tomoyuki; Ohtsuki, Mamitaro

2018-04-25

Interleukin (IL)-33 is released on cell injury and activates the immune reaction. IL-33 is involved in antiviral reaction in herpes virus infection, but the source that secretes IL-33 has not been identified. We speculate that keratinocytes injured in herpes virus infection secrete IL-33. In order to detect IL-33 in the lesional epidermis of patients with herpes virus infection, we immunostained several cutaneous herpes virus infection samples with an anti-IL-33 antibody, and compared them with cutaneous human papilloma virus (HPV) infection samples. We observed strong nuclear and mild cytoplasmic staining in epidermal keratinocytes of the lesional skin samples with herpes simplex virus and varicella zoster virus infections. However, staining was not observed in the epidermis of verruca vulgaris (VV) samples. We assumed that the strong immune reaction to herpes virus infection may depend on strong IL-33 expression in the epidermis, while very weak immune reaction in samples from patients with VV may be due to low or no expression of IL-33 in the lesional epidermis. © 2018 Japanese Dermatological Association.

Altered E-Cadherin Levels and Distribution in Melanocytes Precede Clinical Manifestations of Vitiligo.

PubMed

Wagner, Roselyne Y; Luciani, Flavie; Cario-André, Muriel; Rubod, Alain; Petit, Valérie; Benzekri, Laila; Ezzedine, Khaled; Lepreux, Sébastien; Steingrimsson, Eirikur; Taieb, A; Gauthier, Yvon; Larue, Lionel; Delmas, Véronique

2015-07-01

Vitiligo is the most common depigmenting disorder resulting from the loss of melanocytes from the basal epidermal layer. The pathogenesis of the disease is likely multifactorial and involves autoimmune causes, as well as oxidative and mechanical stress. It is important to identify early events in vitiligo to clarify pathogenesis, improve diagnosis, and inform therapy. Here, we show that E-cadherin (Ecad), which mediates the adhesion between melanocytes and keratinocytes in the epidermis, is absent from or discontinuously distributed across melanocyte membranes of vitiligo patients long before clinical lesions appear. This abnormality is associated with the detachment of the melanocytes from the basal to the suprabasal layers in the epidermis. Using human epidermal reconstructed skin and mouse models with normal or defective Ecad expression in melanocytes, we demonstrated that Ecad is required for melanocyte adhesiveness to the basal layer under oxidative and mechanical stress, establishing a link between silent/preclinical, cell-autonomous defects in vitiligo melanocytes and known environmental stressors accelerating disease expression. Our results implicate a primary predisposing skin defect affecting melanocyte adhesiveness that, under stress conditions, leads to disappearance of melanocytes and clinical vitiligo. Melanocyte adhesiveness is thus a potential target for therapy aiming at disease stabilization.

Whole-exome sequencing in a single proband reveals a mutation in the CHST8 gene in autosomal recessive peeling skin syndrome

PubMed Central

Cabral, Rita M.; Kurban, Mazen; Wajid, Muhammad; Shimomura, Yutaka; Petukhova, Lynn; Christiano, Angela M.

2015-01-01

Generalized peeling skin syndrome (PSS) is an autosomal recessive genodermatosis characterized by lifelong, continuous shedding of the upper epidermis. Using whole-genome homozygozity mapping and whole-exome sequencing, we identified a novel homozygous missense mutation (c.229C>T, R77W) within the CHST8 gene, in a large consanguineous family with non-inflammatory PSS type A. CHST8 encodes a Golgi transmembrane N-acetylgalactosamine-4-O-sulfotransferase (GalNAc4-ST1), which we show by immunofluorescence staining to be expressed throughout normal epidermis. A colorimetric assay for total sulfated glycosaminoglycan (GAG) quantification, comparing human keratinocytes (CCD1106 KERTr) expressing wild type and mutant recombinant GalNAc4-ST1, revealed decreased levels of total sulfated GAGs in cells expressing mutant GalNAc4-ST1, suggesting loss of function. Western blotting revealed lower expression levels of mutant recombinant GalNAc4-ST1 compared to wild type, suggesting that accelerated degradation may result in loss of function, leading to PSS type A. This is the first report describing a mutation as the cause of PSS type A. PMID:22289416

Whole-exome sequencing in a single proband reveals a mutation in the CHST8 gene in autosomal recessive peeling skin syndrome.

PubMed

Cabral, Rita M; Kurban, Mazen; Wajid, Muhammad; Shimomura, Yutaka; Petukhova, Lynn; Christiano, Angela M

2012-04-01

Generalized peeling skin syndrome (PSS) is an autosomal recessive genodermatosis characterized by lifelong, continuous shedding of the upper epidermis. Using whole-genome homozygozity mapping and whole-exome sequencing, we identified a novel homozygous missense mutation (c.229C>T, R77W) within the CHST8 gene, in a large consanguineous family with non-inflammatory PSS type A. CHST8 encodes a Golgi transmembrane N-acetylgalactosamine-4-O-sulfotransferase (GalNAc4-ST1), which we show by immunofluorescence staining to be expressed throughout normal epidermis. A colorimetric assay for total sulfated glycosaminoglycan (GAG) quantification, comparing human keratinocytes (CCD1106 KERTr) expressing wild type and mutant recombinant GalNAc4-ST1, revealed decreased levels of total sulfated GAGs in cells expressing mutant GalNAc4-ST1, suggesting loss of function. Western blotting revealed lower expression levels of mutant recombinant GalNAc4-ST1 compared to wild type, suggesting that accelerated degradation may result in loss of function, leading to PSS type A. This is the first report describing a mutation as the cause of PSS type A. Copyright © 2012 Elsevier Inc. All rights reserved.

UV decreases the synthesis of free fatty acids and triglycerides in the epidermis of human skin in vivo, contributing to development of skin photoaging.

PubMed

Kim, Eun Ju; Jin, Xing-Ji; Kim, Yeon Kyung; Oh, In Kyung; Kim, Ji Eun; Park, Chi-Hyun; Chung, Jin Ho

2010-01-01

Although fatty acids are known to be important in various skin functions, their roles on photoaging in human skin are poorly understood. We investigated the alteration of lipid metabolism in the epidermis by photoaging and acute UV irradiation in human skin. UV irradiated young volunteers (21-33 years, n=6) and elderly volunteers (70-75 years, n=7) skin samples were obtained by punch biopsy. Then the epidermis was separated from dermis and lipid metabolism was investigated. We observed that the amounts of free fatty acids (FFA) and triglycerides (TG) in the epidermis of photoaged or acutely UV irradiated human skin were significantly decreased. The expressions of genes related to lipid synthesis, including acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD), sterol regulatory element binding proteins (SREBPs), and peroxisome proliferator-activated receptors (PPARgamma) were also markedly decreased. To elucidate the significance of these changes of epidermal lipids in human skin, we investigated the effects of TG or various inhibitors for the enzymes involved in TG synthesis on the expression of matrix metalloproteinase-1 (MMP-1) in cultured human epidermal keratinocytes. We demonstrated that triolein (TG) reduced basal and UV-induced MMP-1 mRNA expression. In addition, each inhibitor for various lipid synthesis enzymes, such as TOFA (ACC inhibitor), cerulenin (FAS inhibitor) and trans-10, cis-12-CLA (SCD inhibitor), increased the MMP-1 expression significantly in a dose-dependent manner. We also demonstrated that triolein could inhibit cerulenin-induced MMP-1 expression. Furthermore, topical application of triolein (10%) significantly prevented UV-induced MMP-13, COX-2, and IL-1beta expression in hairless mice. Our results suggest that TG and FFA may play important roles in photoaging of human skin. Copyright 2009 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Prolonged viability of human organotypic skin explant in culture method (hOSEC)*

PubMed Central

Frade, Marco Andrey Cipriani; de Andrade, Thiago Antônio Moretti; Aguiar, Andréia Fernanda Carvalho Leone; Guedes, Flávia Araújo; Leite, Marcel Nani; Passos, Williane Rodrigues; Coelho, Eduardo Barbosa; Das, Pranab Kummar

2015-01-01

BACKGROUND: Currently, the cosmetic industry is overwhelmed in keeping up with the safety assessment of the increasing number of new products entering the market. To meet such demand, research centers have explored alternative methods to animal testing and also the large number of volunteers necessary for preclinical and clinical tests. OBJECTIVES: This work describes the human skin ex-vivo model (hOSEC: Human Organotypic Skin Explant Culture) as an alternative to test the effectiveness of cosmetics and demonstrate its viability through cutaneous keratinocytes' proliferative capacity up to 75 days in culture. METHODS: The skin explants obtained from surgeries were cultured in CO2-humid incubator. After 1, 7, 30 and 75 days in culture, skin fragments were harvested for analysis with histomorphological exam (HE staining) on all days of follow-up and immunohistochemistry for Ck5/6, Ck10 and Ki-67 only on the 75th day. RESULTS: On the 7th day, the epidermis was perfect in the dermoepidermal junction, showing the viability of the model. On the 30th day, the epidermis was thicker, with fewer layers on the stratum corneum, although the cutaneous structure was unaltered. On the 75th day, the skin became thinner but the dermoepidermal junctions were preserved and epidermal proliferation was maintained. After the 75th day on culture, the skin was similar to normal skin, expressing keratinocytes with Ck5/6 on supra-basal layers; Ck10 on differentiated layers; and viability could be assessed by the positivity of basal cells by Ki-67. CONCLUSION: The hOSEC model seems a good alternative to animal testing; it can be used as a preclinical test analogous to clinical human skin test with similar effectiveness and viability proven by immunohistological analyses. PMID:26131864

Prolonged viability of human organotypic skin explant in culture method (hOSEC).

PubMed

Frade, Marco Andrey Cipriani; Andrade, Thiago Antônio Moretti de; Aguiar, Andréia Fernanda Carvalho Leone; Guedes, Flávia Araújo; Leite, Marcel Nani; Passos, Williane Rodrigues; Coelho, Eduardo Barbosa; Das, Pranab Kummar

2015-01-01

Currently, the cosmetic industry is overwhelmed in keeping up with the safety assessment of the increasing number of new products entering the market. To meet such demand, research centers have explored alternative methods to animal testing and also the large number of volunteers necessary for preclinical and clinical tests. This work describes the human skin ex-vivo model (hOSEC: Human Organotypic Skin Explant Culture) as an alternative to test the effectiveness of cosmetics and demonstrate its viability through cutaneous keratinocytes' proliferative capacity up to 75 days in culture. The skin explants obtained from surgeries were cultured in CO2-humid incubator. After 1, 7, 30 and 75 days in culture, skin fragments were harvested for analysis with histomorphological exam (HE staining) on all days of follow-up and immunohistochemistry for Ck5/6, Ck10 and Ki-67 only on the 75th day. On the 7th day, the epidermis was perfect in the dermoepidermal junction, showing the viability of the model. On the 30th day, the epidermis was thicker, with fewer layers on the stratum corneum, although the cutaneous structure was unaltered. On the 75th day, the skin became thinner but the dermoepidermal junctions were preserved and epidermal proliferation was maintained. After the 75th day on culture, the skin was similar to normal skin, expressing keratinocytes with Ck5/6 on supra-basal layers; Ck10 on differentiated layers; and viability could be assessed by the positivity of basal cells by Ki-67. The hOSEC model seems a good alternative to animal testing; it can be used as a preclinical test analogous to clinical human skin test with similar effectiveness and viability proven by immunohistological analyses.

Expression of the Ly6/uPAR-domain proteins C4.4A and Haldisin in non-invasive and invasive skin lesions.

PubMed

Kriegbaum, Mette C; Clausen, Ole P F; Lærum, Ole D; Ploug, Michael

2015-02-01

C4.4A and Haldisin belong to the Ly6/uPAR/α-neurotoxin protein domain family. They exhibit highly regulated expression profiles in normal epidermis, where they are confined to early (C4.4A) and late (Haldisin) squamous differentiation. We have now explored if dysregulated expressions occur in non-invasive and invasive skin lesions. In non-invasive lesions, their expression signatures were largely maintained as defined by that of normal epidermis. The scenario was, however, markedly different in the progression towards invasive squamous cell carcinomas. In its non-invasive stage (carcinoma in situ), a pronounced attenuation of C4.4A expression was observed, but upon transition to malignant invasive squamous cell carcinomas, the invasive fronts regained high expression of C4.4A. A similar progression was observed for the early stages of benign infiltrating keratoacanthomas. Interestingly, this transition was accompanied by a shift in the predominant association of C4.4A expression with CK1/10 in the normal epidermis to CK5/14 in the invasive lesions. In contrast, Haldisin expression maintained its confinement to the most-differentiated cells and was hardly expressed in the invasive lesions. Because this altered expression of C4.4A was seen in the invasive front of benign (keratoacanthomas) and malignant (squamous cell carcinomas) neoplasms, we propose that this transition of expression is primarily related to the invasive process. © The Author(s) 2014.

Protection against free radicals (UVB irradiation) of a water-soluble enzymatic extract from rice bran. Study using human keratinocyte monolayer and reconstructed human epidermis.

PubMed

Santa-María, C; Revilla, E; Miramontes, E; Bautista, J; García-Martínez, A; Romero, E; Carballo, M; Parrado, J

2010-01-01

The antioxidant capacity of a water-soluble enzymatic extract from rice bran (EERB) has been tested in two cell models: keratinocyte monolayers and human reconstructed epidermis. Cells were incubated in culture medium in presence of different amounts of EERB and were UVB irradiated. Cell population assessment (MTT assay) and MDA (malonaldehyde) production were evaluated. The EERB did not induce cytotoxic effect for concentrations inferior or equal to 100 microg/mL. Human keratinocyte monolayers were protected of irradiation preventing 33% the lipid peroxidation process at concentration of 10 microg/ml of EEBR. In reconstructed human epidermis, 100 microg/mL decreased lipid peroxidation process by 44% (p<0.01) with regards to irradiated negative control. This effect was comparable to that of vitamin E at 600 microg/mL. Our data indicate that EERB is potentially able to efficiently counteract UVB-induced response. The EERB, diluted at 10% with water has very good skin compatibility. This product showed a sun protection factor of 4.8+/-0.3. Thus we can propose EERB as a useful natural standardized extract in skin photoprotection with promising applications in the field of dermatology. Copyright 2009 Elsevier Ltd. All rights reserved.

Sensory transduction and the mammalian epidermis.

PubMed

Hoath, S B; Donnelly, M M; Boissy, R E

1990-01-01

This paper constitutes, in its main intent, an introduction to the mammalian epidermis as a surface for biosensor applications. In particular, the structure and function of the epidermis of the newborn rat are examined as a model for studies of the human state. Data are presented illustrating an anisotropic organization of the dorsal surface of the neonatal rodent with regard to line of tension and thermal gradients. The dependence of the mechanical properties of the epidermis upon calcium is examined by means of an in-vitro assay of epidermal retraction. The potential role of keratin tonofilaments as piezoelectric and pyroelectric elements in the epidermis is introduced and the spatial alignment of these macromolecular arrays is demonstrated to be a function of physiological tensions. These findings are discussed in the context of noninvasive epidermal sensors utilized to understand mechanisms of sensory development and physiological regulation. Optoelectronic (infrared) imaging of the dorsal temperature field and the alteration in this field by treatment with epidermal growth factor are presented as examples of this methodologic approach. It is concluded that a detailed examination of the material and physical properties of mammalian epidermis is a reasonable goal of biosensor development and research. Hypothetically, such studies may reveal important molecular and cellular mechanisms by which sensory data are transmitted or transduced at the organism-environmental interface.

CO2 laser debridement of sulphur mustard (bis-2-chloroethyl sulphide) induced cutaneous lesions accelerates production of a normal epidermis with elimination of cytological atypia.

PubMed

Smith, K J; Skelton, H G; Martin, J L; Hurst, C G; Hackley, B E

1997-10-01

Sulphur mustard (bis-2-chloroethyl sulphide; HD) exposure acutely produces lesions that vary from mild erythema, to blister formation, to necrosis. When blisters occur, with or without necrosis, healing of the lesions is delayed. Weanling pigs exposed to a mild erythema-producing dose of HD and to a moderate erythema-producing dose that consistently gave microblister formation were treated with CO2 laser (Tru-Pulse) debridement at 6, 24 or 48 h after exposure. The histopathological features observed at 14 days after exposure in control skin and skin exposed to both HD doses were compared with the features observed in CO2 laser-debrided skin in non-exposed and HD-exposed skin sites. The overlying epidermis in the non-laser treated lesions was thin, with cytological atypia and squamoid changes within the basal cell layer, as well as scattered apoptotic/necrotic keratinocytes. An increased inflammatory infiltrate and necrobiotic changes in the dermis were seen at the higher HD dose. All laser-treated lesions appeared identical, with a thick, differentiated epidermis and a well-formed basal cell layer. There was minimal inflammatory infiltrate. In the papillary dermis there were increased stromal cells. Laser debridement of mild clinical lesions induced by HD produced a more functional epidermis by 14 days as well as clearing the epidermis of damaged keratinocytes.

The human homeobox genes MSX-1, MSX-2, and MOX-1 are differentially expressed in the dermis and epidermis in fetal and adult skin.

PubMed

Stelnicki, E J; Kömüves, L G; Holmes, D; Clavin, W; Harrison, M R; Adzick, N S; Largman, C

1997-10-01

In order to identify homeobox genes which may regulate skin development and possibly mediate scarless fetal wound healing we have screened amplified human fetal skin cDNAs by polymerase chain reaction (PCR) using degenerate oligonucleotide primers designed against highly conserved regions within the homeobox. We identified three non-HOX homeobox genes, MSX-1, MSX-2, and MOX-1, which were differentially expressed in fetal and adult human skin. MSX-1 and MSX-2 were detected in the epidermis, hair follicles, and fibroblasts of the developing fetal skin by in situ hybridization. In contrast, MSX-1 and MSX-2 expression in adult skin was confined to epithelially derived structures. Immunohistochemical analysis of these two genes suggested that their respective homeoproteins may be differentially regulated. While Msx-1 was detected in the cell nucleus of both fetal and adult skin; Msx-2 was detected as a diffuse cytoplasmic signal in fetal epidermis and portions of the hair follicle and dermis, but was localized to the nucleus in adult epidermis. MOX-1 was expressed in a pattern similar to MSX early in gestation but then was restricted exclusively to follicular cells in the innermost layer of the outer root sheath by 21 weeks of development. Furthermore, MOX-1 expression was completely absent in adult cutaneous tissue. These data imply that each of these homeobox genes plays a specific role in skin development.

Psoriasiform skin disease in transgenic pigs with high-copy ectopic expression of human integrins α2 and β1

PubMed Central

Staunstrup, Nicklas Heine; Stenderup, Karin; Mortensen, Sidsel; Primo, Maria Nascimento; Steiniche, Torben; Liu, Ying; Li, Rong; Schmidt, Mette; Purup, Stig; Dagnæs-Hansen, Frederik; Schrøder, Lisbeth Dahl; Svensson, Lars; Petersen, Thomas Kongstad; Callesen, Henrik; Bolund, Lars

2017-01-01

ABSTRACT Psoriasis is a complex human-specific disease characterized by perturbed keratinocyte proliferation and a pro-inflammatory environment in the skin. Porcine skin architecture and immunity are very similar to that in humans, rendering the pig a suitable animal model for studying the biology and treatment of psoriasis. Expression of integrins, which is normally confined to the basal layer of the epidermis, is maintained in suprabasal keratinocytes in psoriatic skin, modulating proliferation and differentiation as well as leukocyte infiltration. Here, we generated minipigs co-expressing integrins α2 and β1 in suprabasal epidermal layers. Integrin-transgenic minipigs born into the project displayed skin phenotypes that correlated with the number of inserted transgenes. Molecular analyses were in good concordance with histological observations of psoriatic hallmarks, including hypogranulosis and T-lymphocyte infiltration. These findings mark the first creation of minipigs with a psoriasiform phenotype resembling human psoriasis and demonstrate that integrin signaling plays a key role in psoriasis pathology. PMID:28679670

Melanin distribution in human epidermis affords localized protection against DNA photodamage and concurs with skin cancer incidence difference in extreme phototypes.

PubMed

Fajuyigbe, Damilola; Lwin, Su M; Diffey, Brian L; Baker, Richard; Tobin, Desmond J; Sarkany, Robert P E; Young, Antony R

2018-02-02

Epidermal DNA damage, especially to the basal layer, is an established cause of keratinocyte cancers (KCs). Large differences in KC incidence (20- to 60-fold) between white and black populations are largely attributable to epidermal melanin photoprotection in the latter. The cyclobutane pyrimidine dimer (CPD) is the most mutagenic DNA photolesion; however, most studies suggest that melanin photoprotection against CPD is modest and cannot explain the considerable skin color-based differences in KC incidence. Along with melanin quantity, solar-simulated radiation-induced CPD assessed immediately postexposure in the overall epidermis and within 3 epidermal zones was compared in black West Africans and fair Europeans. Melanin in black skin protected against CPD by 8.0-fold in the overall epidermis and by 59.0-, 16.5-, and 5.0-fold in the basal, middle, and upper epidermis, respectively. Protection was related to the distribution of melanin, which was most concentrated in the basal layer of black skin. These results may explain, at least in part, the considerable skin color differences in KC incidence. These data suggest that a DNA protection factor of at least 60 is necessary in sunscreens to reduce white skin KC incidence to a level that is comparable with that of black skin.-Fajuyigbe, D., Lwin, S. M., Diffey, B. L., Baker, R., Tobin, D. J., Sarkany, R. P. E., Young, A. R. Melanin distribution in human epidermis affords localized protection against DNA photodamage and concurs with skin cancer incidence difference in extreme phototypes.

Regulation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity in murine epidermis. Modulation of enzyme content and activation state by barrier requirements.

PubMed Central

Proksch, E; Elias, P M; Feingold, K R

1990-01-01

Epidermal cholesterol biosynthesis is regulated by barrier function. We quantitated the amount and activation state (phosphorylation-dephosphorylation) of the rate-limiting enzyme, 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, in epidermis before and after barrier disruption. In murine epidermis we found high enzyme activity (1.75 +/- 0.02 nmol/min per mg protein). After acute barrier disruption, enzyme activity began to increase after 1.5 h, reaching a maximum increase by 2.5 h, and returned to normal by 15 h. Chronic barrier disruption increased total enzyme activity by 83%. In normal epidermis, measurement of HMG CoA reductase activity in microsomes isolated in NaF- vs. NaCl-containing buffers demonstrated that 46 +/- 2% of the enzyme was in the active form. After acute or chronic barrier disruption, a marked increase in the percentage of HMG CoA reductase in the active form was observed. Acute disruption increased enzyme activation state as early as 15 min, reaching a maximum after 2.5 h, with an increase still present at 15 h, indicating that changes in activation state had a close temporal relationship with barrier function. Increases in total HMG CoA reductase activity occurred only after profound barrier disruption, whereas changes in activation state occur with lesser degrees of barrier disruption. Artificial correction of barrier function prevented the increase in total HMG CoA reductase activity, and partially prevented the increase in enzyme activation. These results show that barrier requirements regulate epidermal cholesterol synthesis by modulating both the HMG CoA reductase amount and activation state. Images PMID:2312730

Comparative study between reconstructed and native human epidermis using nuclear microscopy

NASA Astrophysics Data System (ADS)

Ynsa, M. D.; Gontier, E.; Mavon, A.; Moretto, P.; Rosdy, M.

2006-08-01

The physiological status of native skin is suffering from large inter-individual variations, especially in terms of inorganic ions content. For this reason, together with the advent of ethic laws on animal experimentation, reconstructed skin or epidermis models are extensively employed nowadays in penetration studies for cosmetic or pharmacological applications. It has been already verified that reconstructed human epidermis (RHE) has similar physiological mechanisms to native human skin, but until now, there are few studies where the elemental concentrations of both skins, reconstructed and native, are compared. In this work, freeze-dried thin sections of human native skin obtained from surgery have been characterized using PIXE, RBS and STIM at the CENBG nuclear microprobe. RHE samples were treated and analyzed in the same conditions for comparison. The combination of the different imaging and analysis techniques made possible a clear delimitation and identification of skin ultrastructure. The elemental concentrations of P, S, Cl, K and Ca were measured in the different strata. For both skins, concentrations have been compared and significant differences in terms of elemental concentrations have been determined using statistical approaches. Similar physiological characteristics were pointed out in both skin models, in particular the Ca gradient presumably involved in the regulation of the barrier effect.

Nicotinic Acid Receptor Abnormalities in Human Skin Cancer: Implications for a Role in Epidermal Differentiation

PubMed Central

Bermudez, Yira; Benavente, Claudia A.; Meyer, Ralph G.; Coyle, W. Russell; Jacobson, Myron K.; Jacobson, Elaine L.

2011-01-01

Background Chronic UV skin exposure leads to epidermal differentiation defects in humans that can be largely restored by pharmacological doses of nicotinic acid. Nicotinic acid has been identified as a ligand for the human G-protein-coupled receptors GPR109A and GPR109B that signal through Gi-mediated inhibition of adenylyl cyclase. We have examined the expression, cellular distribution, and functionality of GPR109A/B in human skin and skin derived epidermal cells. Results Nicotinic acid increases epidermal differentiation in photodamaged human skin as judged by the terminal differentiation markers caspase 14 and filaggrin. Both GPR109A and GPR109B genes are transcribed in human skin and in epidermal keratinocytes, but expression in dermal fibroblasts is below limits of detection. Receptor transcripts are greatly over-expressed in squamous cell cancers. Receptor protein in normal skin is prominent from the basal through granular layers of the epidermis, with cellular localization more dispersive in the basal layer but predominantly localized at the plasma membrane in more differentiated epidermal layers. In normal human primary and immortalized keratinocytes, nicotinic acid receptors show plasma membrane localization and functional Gi-mediated signaling. In contrast, in a squamous cell carcinoma derived cell line, receptor protein shows a more diffuse cellular localization and the receptors are nearly non-functional. Conclusions The results of these studies justify future genetic and pharmacological intervention studies to define possible specific role(s) of nicotinic acid receptors in human skin homeostasis. PMID:21655214

Windowless ultrasound photoacoustic cell for in vivo mid-IR spectroscopy of human epidermis: Low interference by changes of air pressure, temperature, and humidity caused by skin contact opens the possibility for a non-invasive monitoring of glucose in the interstitial fluid

NASA Astrophysics Data System (ADS)

Pleitez, Miguel A.; Lieblein, Tobias; Bauer, Alexander; Hertzberg, Otto; von Lilienfeld-Toal, Hermann; Mäntele, Werner

2013-08-01

The application of a novel open, windowless cell for the photoacoustic infrared spectroscopy of human skin is described. This windowless cavity is tuned for optimum performance in the ultrasound range between 50 and 60 kHz. In combination with an external cavity tunable quantum cascade laser emitting in the range from ˜1000 cm-1 to 1245 cm-1, this approach leads to high signal-to-noise-ratio (SNR) for mid-infrared spectra of human skin. This opens the possibility to measure in situ the absorption spectrum of human epidermis in the mid-infrared region at high SNR in a few (˜5) seconds. Rapid measurement of skin spectra greatly reduces artifacts arising from movements. As compared to closed resonance cells, the windowless cell exhibits the advantage that the influence of air pressure variations, temperature changes, and air humidity buildup that are caused by the contact of the cell to the skin surface can be minimized. We demonstrate here that this approach can be used for continuous and non-invasive monitoring of the glucose level in human epidermis, and thus may form the basis for a non-invasive monitoring of the glucose level for diabetes patients.

Regenerated keratin membrane to match the in vitro drug diffusion through human epidermis

PubMed Central

Selmin, Francesca; Cilurzo, Francesco; Aluigi, Annalisa; Franzè, Silvia; Minghetti, Paola

2012-01-01

This work aimed to develop membranes made of regenerated keratin and ceramides (CERs) to match the barrier property of the human stratum corneum in in vitro percutaneous absorption studies. The membrane composition was optimized on the basis of the in vitro drug diffusion profiles of ibuprofen, propranolol and testosterone chosen as model drugs on the basis of their different diffusion and solubility properties. The data were compared to those obtained using human epidermis. The ATR-FTIR and SEM analyses revealed that CERs were suspended into the regenerated keratin matrix, even if a partial solubilization occurred. It resulted in the membranes being physically stable after exposure to aqueous buffer and/or mineral oil and the fluxes of ibuprofen and propranolol from these vehicles through membranes and human skin were of the same order of magnitude. The best relationship with human epidermis data was obtained with 180 μm-thick membrane containing 1% ceramide III and 1% ceramide VI. The data on the testosterone diffusion were affected by the exposure of the membrane to a water/ethanol solution over a prolonged period of time, indicating that such an organic solvent was able to modify the supermolecular organization of keratin and CERs. The keratin/CER membranes can represent a simplified model to assay the in vitro skin permeability study of small molecules. PMID:25755997

Epidermal regulation of dermal fibroblast activity.

PubMed

Garner, W L

1998-07-01

Although the association between delayed burn wound healing and subsequent hypertrophic scar formation is well-established, the mechanism for this relationship is unknown. Unhealed burn wounds lack an epidermis, suggesting a possible regulatory role for the epidermis in controlling dermal fibroblast matrix synthesis. Therefore, we examined the effect of epidermal cells and media conditioned by epidermal cells on fibroblast collagen synthesis and replication. Purified fibroblast and keratinocyte cell strains were developed from discarded normal adult human skin. Conditioned media were created by incubation of cytokine-free and serum-free medium with either confluent fibroblast or keratinocyte cultures for 18 hours (n = 3). Nearly confluent fibroblast cultures were exposed for 48 hours to graded concentrations of either unconditioned medium (control), conditioned medium, or varying numbers of keratinocytes. Replication was quantified by the incorporation of 3H-thymidine. Collagen synthesis was measured by the incorporation of 3H-proline into collagenase-sensitive protein. Data were compared using analysis of variance (ANOVA) and linear regression. Keratinocyte conditioned medium induced a significant increase in replication (n = 3) (p = 0.004) and a decrease in collagen synthesis (n = 6) (p < 0.001). In contrast, neither fibroblast conditioned medium nor control medium had an effect on fibroblast replication or collagen synthesis. Co-culture of fibroblast with a graded number of keratinocytes similarly decreased collagen synthesis (n = 6) (p < 0.001). Dermal fibroblast collagen synthesis appears to be regulated by a soluble keratinocyte product. This result suggests a mechanism for the clinical observation that unhealed burn wounds, which lack the epidermis, demonstrate excess collagen production and scar. Clinical strategies to decrease hypertrophic scar should include an attempt at early wound closure with skin grafting or the application of cultured epithelial autografts.

Nonlinear cellular dynamics of keratinocytes in normal and psoriatic epidermis under action of UV radiation

NASA Astrophysics Data System (ADS)

Stolnitz, Mikhail M.; Medvedev, Boris A.; Gribko, Tatyana V.

2004-05-01

The semi-phenomenological model of epidermal cell dynamics is submitted. The model takes into account three types of basal layer keratinocytes (stem, transient amplifying, terminally differentiated), distribution of first two types cells on mitotic cycle stages and resting states, keratinocytes-lymphocytes interactions that provide a positive feedback loop, influence of more differentiated cells on their progenitors that provide a negative feedback loop. Simplified model are developed and its stationary solutions are received. The opportunity of interpretation of some received modes as corresponding to various stages of psoriasis is discussed. Influence of UV-radiation on transitions between various modes of epidermis functioning is qualitatively analyzed.

Hair Follicle and Sebaceous Gland De Novo Regeneration With Cultured Epidermal Stem Cells and Skin-Derived Precursors.

PubMed

Wang, Xiaoxiao; Wang, Xusheng; Liu, Jianjun; Cai, Ting; Guo, Ling; Wang, Shujuan; Wang, Jinmei; Cao, Yanpei; Ge, Jianfeng; Jiang, Yuyang; Tredget, Edward E; Cao, Mengjun; Wu, Yaojiong

2016-12-01

: Stem cell-based organ regeneration is purported to enable the replacement of impaired organs in the foreseeable future. Here, we demonstrated that a combination of cultured epidermal stem cells (Epi-SCs) derived from the epidermis and skin-derived precursors (SKPs) was capable of reconstituting functional hair follicles and sebaceous glands (SG). When Epi-SCs and SKPs were mixed in a hydrogel and implanted into an excisional wound in nude mice, the Epi-SCs formed de novo epidermis along with hair follicles, and SKPs contributed to dermal papilla in the neogenic hair follicles. Notably, a combination of culture-expanded Epi-SCs and SKPs derived from the adult human scalp were sufficient to generate hair follicles and hair. Bone morphogenetic protein 4, but not Wnts, sustained the expression of alkaline phosphatase in SKPs in vitro and the hair follicle-inductive property in vivo when SKPs were engrafted with neonatal epidermal cells into excisional wounds. In addition, Epi-SCs were capable of differentiating into sebocytes and formed de novo SGs, which excreted lipids as do normal SGs. Thus our results indicate that cultured Epi-SCs and SKPs are sufficient to generate de novo hair follicles and SGs, implying great potential to develop novel bioengineered skin substitutes with appendage genesis capacity. In postpartum humans, skin appendages lost in injury are not regenerated, despite the considerable achievement made in skin bioengineering. In this study, transplantation of a combination of culture-expanded epidermal stem cells and skin-derived progenitors from mice and adult humans led to de novo regeneration of functional hair follicles and sebaceous glands. The data provide transferable knowledge for the development of novel bioengineered skin substitutes with epidermal appendage regeneration capacity. ©AlphaMed Press.

Hair Follicle and Sebaceous Gland De Novo Regeneration With Cultured Epidermal Stem Cells and Skin-Derived Precursors

PubMed Central

Wang, Xiaoxiao; Wang, Xusheng; Liu, Jianjun; Cai, Ting; Guo, Ling; Wang, Shujuan; Wang, Jinmei; Cao, Yanpei; Ge, Jianfeng; Jiang, Yuyang; Tredget, Edward E.; Cao, Mengjun

2016-01-01

Stem cell-based organ regeneration is purported to enable the replacement of impaired organs in the foreseeable future. Here, we demonstrated that a combination of cultured epidermal stem cells (Epi-SCs) derived from the epidermis and skin-derived precursors (SKPs) was capable of reconstituting functional hair follicles and sebaceous glands (SG). When Epi-SCs and SKPs were mixed in a hydrogel and implanted into an excisional wound in nude mice, the Epi-SCs formed de novo epidermis along with hair follicles, and SKPs contributed to dermal papilla in the neogenic hair follicles. Notably, a combination of culture-expanded Epi-SCs and SKPs derived from the adult human scalp were sufficient to generate hair follicles and hair. Bone morphogenetic protein 4, but not Wnts, sustained the expression of alkaline phosphatase in SKPs in vitro and the hair follicle-inductive property in vivo when SKPs were engrafted with neonatal epidermal cells into excisional wounds. In addition, Epi-SCs were capable of differentiating into sebocytes and formed de novo SGs, which excreted lipids as do normal SGs. Thus our results indicate that cultured Epi-SCs and SKPs are sufficient to generate de novo hair follicles and SGs, implying great potential to develop novel bioengineered skin substitutes with appendage genesis capacity. Significance In postpartum humans, skin appendages lost in injury are not regenerated, despite the considerable achievement made in skin bioengineering. In this study, transplantation of a combination of culture-expanded epidermal stem cells and skin-derived progenitors from mice and adult humans led to de novo regeneration of functional hair follicles and sebaceous glands. The data provide transferable knowledge for the development of novel bioengineered skin substitutes with epidermal appendage regeneration capacity. PMID:27458264

[Decolorization of skin and hair-derived melanin by three ligninolytic enzymes].

PubMed

Miao, F; Lei, T C; Su, M Y; Yi, W J; Jiang, S; Xu, S Z

2017-11-21

Objective: To compare the decolorization efficiency of lignin peroxidase (LiP), manganese peroxidase (MnP) and laccase on eumelanin and pheomelanin, and to investigate the effect of topical administration of LiP solution on hyperpigmented guinea pigs skin induced by 308 nm excimer light. Methods: Pheomelanin-enriched specimens were prepared from human hair and cutaneous melanoma tissue using alkaline lysis method.Synthetic eumelanin was purchased from a commercial supplier.The same amount (0.02%) of melanin was incubated with the equal enzyme activity (0.2 U/ml) of ligninolytic enzymes for 3 h respectively.The absorbance at 475 nm ( A (475)) in the enzyme-catalyzed solution was measured using ELISA microplate reader.The experimental hyperpigmentation model was established in the dorsal skin of brownish guinea pigs using 308 nm excimer light radiation.LiP and heat-inactivated LiP solution were topically applied at each site.Meanwhile, 3% hydroquinone and vehicle cream were used as control.The skin color (L value) was recorded using a CR-10 Minolta chromameter.Corneocytes were collected using adhesive taping method.The amount and distribution of melanin in the corneocytes and skin tissues was visualized by Fontana-Masson staining. Results: All three ligninolytic enzymes showed various degree of eumelanin and pheomelanin decolorization activity.The decolorization activity of LiP, MnP and laccase was 40%-70%, 22%-42% and 9%-21%, respectively.The similar lightening was shown in the skin treated with LiP solution and 3% hydroquinone.The amount of melanin granules in the corneocytes was 199±11 by LiP, which was less than that in untreated control (923±12) and heat-inactive control (989±13). The amount of melanin was decreased in the whole epidermis treated with hydroquinone, the epidermis thickness was increased as well. In contrast, melanin of LiP group was decreased only in the superficial epidermis, the epidermis thickness seemed to be normal. Conclusion: LiP exerts a potent decolorization activity for hair- or skin-derived pheomelanin as well as eumelanin.It remains to be further investigated whether LiP serves as a substitute for hydroquinone in skin lightening products.

In Vitro Dermal Safety Assessment of Silver Nanowires after Acute Exposure: Tissue vs. Cell Models

PubMed Central

Grichine, Alexei; Rachidi, Walid; Charlet, Laurent

2018-01-01

Silver nanowires (AgNW) are attractive materials that are anticipated to be incorporated into numerous consumer products such as textiles, touchscreen display, and medical devices that could be in direct contact with skin. There are very few studies on the cellular toxicity of AgNW and no studies that have specifically evaluated the potential toxicity from dermal exposure. To address this question, we investigated the dermal toxicity after acute exposure of polymer-coated AgNW with two sizes using two models, human primary keratinocytes and human reconstructed epidermis. In keratinocytes, AgNW are rapidly and massively internalized inside cells leading to dose-dependent cytotoxicity that was not due to Ag+ release. Analysing our data with different dose metrics, we propose that the number of NW is the most appropriate dose-metric for studies of AgNW toxicity. In reconstructed epidermis, the results of a standard in vitro skin irritation assay classified AgNW as non-irritant to skin and we found no evidence of penetration into the deeper layer of the epidermis. The findings show that healthy and intact epidermis provides an effective barrier for AgNW, although the study does not address potential transport through follicles or injured skin. The combined cell and tissue model approach used here is likely to provide an important methodology for assessing the risks for skin exposure to AgNW from consumer products. PMID:29641466

In Vitro Dermal Safety Assessment of Silver Nanowires after Acute Exposure: Tissue vs. Cell Models.

PubMed

Lehmann, Sylvia G; Gilbert, Benjamin; Maffeis, Thierry Gg; Grichine, Alexei; Pignot-Paintrand, Isabelle; Clavaguera, Simon; Rachidi, Walid; Seve, Michel; Charlet, Laurent

2018-04-11

Silver nanowires (AgNW) are attractive materials that are anticipated to be incorporated into numerous consumer products such as textiles, touchscreen display, and medical devices that could be in direct contact with skin. There are very few studies on the cellular toxicity of AgNW and no studies that have specifically evaluated the potential toxicity from dermal exposure. To address this question, we investigated the dermal toxicity after acute exposure of polymer-coated AgNW with two sizes using two models, human primary keratinocytes and human reconstructed epidermis. In keratinocytes, AgNW are rapidly and massively internalized inside cells leading to dose-dependent cytotoxicity that was not due to Ag⁺ release. Analysing our data with different dose metrics, we propose that the number of NW is the most appropriate dose-metric for studies of AgNW toxicity. In reconstructed epidermis, the results of a standard in vitro skin irritation assay classified AgNW as non-irritant to skin and we found no evidence of penetration into the deeper layer of the epidermis. The findings show that healthy and intact epidermis provides an effective barrier for AgNW, although the study does not address potential transport through follicles or injured skin. The combined cell and tissue model approach used here is likely to provide an important methodology for assessing the risks for skin exposure to AgNW from consumer products.

Skin Barrier Development Depends on CGI-58 Protein Expression during Late-Stage Keratinocyte Differentiation

PubMed Central

Grond, Susanne; Radner, Franz P.W.; Eichmann, Thomas O.; Kolb, Dagmar; Grabner, Gernot F.; Wolinski, Heimo; Gruber, Robert; Hofer, Peter; Heier, Christoph; Schauer, Silvia; Rülicke, Thomas; Hoefler, Gerald; Schmuth, Matthias; Elias, Peter M.; Lass, Achim; Zechner, Rudolf; Haemmerle, Guenter

2017-01-01

Adipose triglyceride lipase (ATGL) and its coactivator comparative gene identification-58 (CGI-58) are limiting in cellular triglyceride catabolism. Although ATGL deficiency is compatible with normal skin development, mice globally lacking CGI-58 die postnatally and exhibit a severe epidermal permeability barrier defect, which may originate from epidermal and/or peripheral changes in lipid and energy metabolism. Here, we show that epidermis-specific disruption of CGI-58 is sufficient to provoke a defect in the formation of a functional corneocyte lipid envelope linked to impaired ω-O-acylceramide synthesis. As a result, epidermis-specific CGI-58-deficient mice show severe skin dysfunction, arguing for a tissue autonomous cause of disease development. Defective skin permeability barrier formation in global CGI-58-deficient mice could be reversed via transgenic restoration of CGI-58 expression in differentiated but not basal keratinocytes suggesting that CGI-58 is essential for lipid metabolism in suprabasal epidermal layers. The compatibility of ATGL deficiency with normal epidermal function indicated that CGI-58 may stimulate an epidermal triglyceride lipase beyond ATGL required for the adequate provision of fatty acids as a substrate for ω-O-acylceramide synthesis. Pharmacological inhibition of ATGL enzyme activity similarly reduced triglyceride-hydrolytic activities in wild-type and CGI-58 overexpressing epidermis implicating that CGI-58 participates in ω-O-acylceramide biogenesis independent of its role as a coactivator of epidermal triglyceride catabolism. PMID:27725204

Two years of Functional Electrical Stimulation by large surface electrodes for denervated muscles improve skin epidermis in SCI

PubMed Central

Albertin, Giovanna; Kern, Helmut; Hofer, Christian; Guidolin, Diego; Porzionato, Andrea; Rambaldo, Anna; Caro, Raffaele De; Piccione, Francesco; Marcante, Andrea; Zampieri, Sandra

2018-01-01

Our previous studies have shown that severely atrophic Quadriceps muscles of spinal cord injury (SCI) patients suffering with complete conus and cauda equina lesions, and thus with permanent denervation-induced atrophy and degeneration of muscle fibers, were almost completely rescued to normal size after two years of home-based Functional Electrical Stimulation (h-bFES). Since we used large surface electrodes to stimulate the thigh muscles, we wanted to know if the skin was affected by long-term treatment. Here we report preliminary data of morphometry of skin biopsies harvested from legs of 3 SCI patients before and after two years of h-bFES to determine the total area of epidermis in transverse skin sections. By this approach we support our recently published results obtained randomly measuring skin thickness in the same biopsies after H-E stain. The skin biopsies data of three subjects, taken together, present indeed a statistically significant 30% increase in the area of the epidermis after two years of h-bFES. In conclusion, we confirm a long term positive modulation of electrostimulated epidermis, that correlates with the impressive improvements of the FES-induced muscle strength and bulk, and of the size of the muscle fibers after 2-years of h-bFES. PMID:29686823

Absorption spectra and light penetration depth of normal and pathologically altered human skin

NASA Astrophysics Data System (ADS)

Barun, V. V.; Ivanov, A. P.; Volotovskaya, A. V.; Ulashchik, V. S.

2007-05-01

A three-layered skin model (stratum corneum, epidermis, and dermis) and engineering formulas for radiative transfer theory are used to study absorption spectra and light penetration depths of normal and pathologically altered skin. The formulas include small-angle and asymptotic approximations and a layer-addition method. These characteristics are calculated for wavelengths used for low-intensity laser therapy. We examined several pathologies such as vitiligo, edema, erythematosus lupus, and subcutaneous wound, for which the bulk concentrations of melanin and blood vessels or tissue structure (for subcutaneous wound) change compared with normal skin. The penetration depth spectrum is very similar to the inverted blood absorption spectrum. In other words, the depth is minimal at blood absorption maxima. The calculated absorption spectra enable the power and irradiation wavelength providing the required light effect to be selected. Relationships between the penetration depth and the diffuse reflectance coefficient of skin (unambiguously expressed through the absorption coefficient) are analyzed at different wavelengths. This makes it possible to find relationships between the light fields inside and outside the tissue.

Transcriptional effect of an Aframomum angustifolium seed extract on human cutaneous cells using low-density DNA chips.

PubMed

Bonnet-Duquennoy, Mathilde; Dumas, Marc; Debacker, Adeline; Lazou, Kristell; Talbourdet, Sylvie; Franchi, Jocelyne; Heusèle, Catherine; André, Patrice; Schnebert, Sylvianne; Bonté, Frédéric; Kurfürst, Robin

2007-06-01

Studying photoexposed and photoprotected skin biopsies from young and aged women, it has been found that a specific zone, composed of the basal layers of the epidermis, the dermal epidermal junction, and the superficial dermis, is major target of aging and reactive oxygen species. We showed that this zone is characterized by significant variations at a transcriptional and/or protein levels. Using low-density DNA chip technology, we evaluated the effect of a natural mixture of Aframomum angustifolium seed extract containing labdane diterpenoids on these aging markers. Expression profiles of normal human fibroblasts (NHF) were studied using a customized cDNA macroarray system containing genes covering dermal structure, inflammatory responses, and oxidative stress defense mechanisms. For normal human keratinocyte (NHK) investigations, we chose OLISA technique, a sensitive and quantitative method developed by BioMérieux specifically designed to investigate cell death, proliferation, epidermal structure, differentiation, and oxidative stress defense response. We observed that this extract strongly modified gene expression profiles of treated NHK, but weakly for NHF. This extract regulated antioxidant defenses, dermal-epidermal junction components, and epidermal renewal-related genes. Using low-density DNA chip technology, we identified new potential actions of A. angustifolium seed extract on skin aging.

Bifidobacterium-fermented soy milk extract stimulates hyaluronic acid production in human skin cells and hairless mouse skin.

PubMed

Miyazaki, K; Hanamizu, T; Iizuka, R; Chiba, K

2003-01-01

We examined the effects of Bifidobasterium-fermented (BE) and nonfermented (SME) soy milk extracts on the production of hyaluronic acid (HA) in vitro and in vivo. BE, but not SME, significantly enhanced the production of HA in monolayer and organotypic cultures of human keratinocytes, in cultures of human skin fibroblasts, and in hairless mouse skin following topical application for 2 weeks. In the organotypic cultures formed by a similar structure to human epidermis, BE also extended the distribution of HA. Genistein and daidzein, known to stimulate HA production, were detected in BE at a concentration of 0.18 and 0.07 mM, respectively, but not in SME. Therefore, BE has the potential to enhance HA production in the epidermis and dermis, mainly due to genistein released from its glycoside during fermentation. BE is expected to prevent the age-dependent loss of cutaneous HA. Copyright 2003 S. Karger AG, Basel

Immunohistochemical Evaluation of Leptin Expression in Wound Healing: A Clue to Exuberant Scar Formation.

PubMed

Seleit, Iman; Bakry, Ola A; Samaka, Rehab M; Tawfik, Amira S

2016-04-01

Leptin has been recognized as an important factor for promoting normal cutaneous wound healing. The aim of this work was to explore leptin expression in keloid and hypertrophic scars (HS) compared with surgical scars and normal skin. The relationship of this expression with clinicopathologic parameters of studied cases was also evaluated. Using immunohistochemical techniques, leptin was analyzed in skin biopsies of 60 nonobese subjects without metabolic syndrome who presented with keloids (20), HS (20), and surgical scars (20). Twenty normal skin samples, from age-matched, sex-matched, and body mass index-matched subjects, were enrolled as a control group. Leptin showed positive immunoreactivity in epidermis in all cases of surgical scars and keloids and in 75% of HS cases. Dermal expression in fibroblasts, inflammatory cells, and endothelial cells was positive in all cases of surgical scars and keloids and in 70% of HS cases. Leptin was overexpressed in keloids and HS compared with normal skin in epidermis (P<0.001 for both) and dermis (P<0.001 for both) and to surgical scars both in epidermis (P=0.0006, P=0.01, respectively) and dermis (P=0.0001, P=0.001, respectively). Higher leptin H score was significantly associated with older age (P=0.02) and positive family history (P=0.002) in keloid cases and with axial site in keloid and HS cases (P=0.001, P=0.02, respectively). Significant positive correlation was noted between epidermal and dermal leptin H scores in keloids (r=+0.37, P=0.04) and HS (r=+0.39, P=0.02). This may be due to epithelial-mesenchymal interactions in scar pathogenesis. In conclusion, in situ leptin overexpression may increase the possibility of keloid and HS occurrence through altered cytokine production and prolonged healing phases with excessive deposition and delayed collagen degradation. This may open an avenue for research for new therapeutic modalities based on its inhibition.

Psoriasiform skin disease in transgenic pigs with high-copy ectopic expression of human integrins α2 and β1.

PubMed

Staunstrup, Nicklas Heine; Stenderup, Karin; Mortensen, Sidsel; Primo, Maria Nascimento; Rosada, Cecilia; Steiniche, Torben; Liu, Ying; Li, Rong; Schmidt, Mette; Purup, Stig; Dagnæs-Hansen, Frederik; Schrøder, Lisbeth Dahl; Svensson, Lars; Petersen, Thomas Kongstad; Callesen, Henrik; Bolund, Lars; Mikkelsen, Jacob Giehm

2017-07-01

Psoriasis is a complex human-specific disease characterized by perturbed keratinocyte proliferation and a pro-inflammatory environment in the skin. Porcine skin architecture and immunity are very similar to that in humans, rendering the pig a suitable animal model for studying the biology and treatment of psoriasis. Expression of integrins, which is normally confined to the basal layer of the epidermis, is maintained in suprabasal keratinocytes in psoriatic skin, modulating proliferation and differentiation as well as leukocyte infiltration. Here, we generated minipigs co-expressing integrins α2 and β1 in suprabasal epidermal layers. Integrin-transgenic minipigs born into the project displayed skin phenotypes that correlated with the number of inserted transgenes. Molecular analyses were in good concordance with histological observations of psoriatic hallmarks, including hypogranulosis and T-lymphocyte infiltration. These findings mark the first creation of minipigs with a psoriasiform phenotype resembling human psoriasis and demonstrate that integrin signaling plays a key role in psoriasis pathology. © 2017. Published by The Company of Biologists Ltd.

Ultrastructural identification of Langerhans cells in normal swine epidermis.

PubMed Central

Romano, J; Balaguer, L

1991-01-01

Langerhans cells of the epidermis of 6-month-old white crossbred farm pigs were identified by electron microscopy. Ultrastructurally they were similar to those described in other mammals. They were present in basal and suprabasal layers and were characterised by a lobulated nucleus and an electrolucent cytoplasm with occasional dendritic processes, and the absence of tonofilaments and specialised unions with surrounding keratinocytes. They were specifically identified by the presence of characteristic rod or racquet-shaped intracytoplasmic granules. Intraepidermal clear cells without specific granules were present, although no melanocytes were observed. This is the first report of the presence of Birbeck granules in porcine Langerhans cells. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:1817140

Full-Thickness Skin Wound Healing Using Human Placenta-Derived Extracellular Matrix Containing Bioactive Molecules

PubMed Central

Choi, Ji Suk; Kim, Jae Dong; Yoon, Hyun Soo

2013-01-01

The human placenta, a complex organ, which facilitates exchange between the fetus and the mother, contains abundant extracellular matrix (ECM) components and well-preserved endogenous growth factors. In this study, we designed a new dermal substitute from human placentas for full-thickness wound healing. Highly porous, decellularized ECM sheets were fabricated from human placentas via homogenization, centrifugation, chemical and enzymatic treatments, molding, and freeze-drying. The physical structure and biological composition of human placenta-derived ECM sheets dramatically supported the regeneration of full-thickness wound in vivo. At the early stage, the ECM sheet efficiently absorbed wound exudates and tightly attached to the wound surface. Four weeks after implantation, the wound was completely closed, epidermic cells were well arranged and the bilayer structure of the epidermis and dermis was restored. Moreover, hair follicles and microvessels were newly formed in the ECM sheet-implanted wounds. Overall, the ECM sheet produced a dermal substitute with similar cellular organization to that of normal skin. These results suggest that human placenta-derived ECM sheets provide a microenvironment favorable to the growth and differentiation of cells, and positive modulate the healing of full-thickness wounds. PMID:22891853

Hyaluronan Does Not Regulate Human Epidermal Keratinocyte Proliferation and Differentiation*

PubMed Central

Malaisse, Jérémy; Pendaries, Valérie; Hontoir, Fanny; De Glas, Valérie; Van Vlaender, Daniel; Simon, Michel; Lambert de Rouvroit, Catherine; Poumay, Yves; Flamion, Bruno

2016-01-01

Hyaluronan (HA) is synthesized by three HA synthases (HAS1, HAS2, and HAS3) and secreted in the extracellular matrix. In human skin, large amounts of HA are found in the dermis. HA is also synthesized by keratinocytes in the epidermis, although its epidermal functions are not clearly identified yet. To investigate HA functions, we studied the effects of HA depletion on human keratinocyte physiology within in vitro reconstructed human epidermis. Inhibition of HA synthesis with 4-methylumbelliferone (4MU) did not modify the expression profile of the epidermal differentiation markers involucrin, keratin 10, and filaggrin during tissue reconstruction. In contrast, when keratinocytes were incubated with 4MU, cell proliferation was decreased. In an attempt to rescue the proliferation function, HA samples of various mean molecular masses were added to keratinocyte cultures treated with 4MU. These samples were unable to rescue the initial proliferation rate. Furthermore, treatments with HA-specific hyaluronidase, although removing almost all HA from keratinocyte cultures, did not alter the differentiation or proliferation processes. The differences between 4MU and hyaluronidase effects did not result from differences in intracellular HA, sulfated glycosaminoglycan concentration, apoptosis, or levels of HA receptors, all of which remained unchanged. Similarly, knockdown of UDP-glucose 6-dehydrogenase (UGDH) using lentiviral shRNA effectively decreased HA production but did not affect proliferation rate. Overall, these data suggest that HA levels in the human epidermis are not directly correlated with keratinocyte proliferation and differentiation and that incubation of cells with 4MU cannot equate with HA removal. PMID:26627828

Soft epidermis of a scaleless snake lacks beta-keratin.

PubMed

Toni, M; Alibardi, L

2007-01-01

Beta-keratins are responsible for the mechanical resistance of scales in reptiles. In a scaleless crotalus snake (Crotalus atrox), large areas of the skin are completely devoid of scales, and the skin appears delicate and wrinkled. The epidermis of this snake has been assessed for the presence of beta-keratin by immunocytochemistry and immunoblotting using an antibody against chicken scale beta-keratin. This antibody recognizes beta-keratins in normal snake scales with molecular weights of 15-18 kDa and isoelectric points at 6.8, 7.5, 8.3 and 9.4. This indicates that beta-keratins of the stratum corneum are mainly basic proteins, so may interact with cytokeratins of the epidermis, most of which appear acidic (isoelectric points 4.5-5.5). A beta-layer and beta-keratin immunoreactivity are completely absent in moults of the scaleless mutant, and the corneous layer comprises a multi-layered alpha-layer covered by a flat oberhautchen. In conclusion, the present study shows that a lack of beta-keratins is correlated with the loss of scales and mechanical protection in the skin of this mutant snake.

Bathing in carbon dioxide-enriched water alters protein expression in keratinocytes of skin tissue in rats.

PubMed

Kälsch, Julia; Pott, Leona L; Takeda, Atsushi; Kumamoto, Hideo; Möllmann, Dorothe; Canbay, Ali; Sitek, Barbara; Baba, Hideo A

2017-04-01

Beneficial effects of balneotherapy using naturally occurring carbonated water (CO 2 enriched) have been known since the Middle Ages. Although this therapy is clinically applied for peripheral artery disease and skin disorder, the underlying mechanisms are not fully elucidated.Under controlled conditions, rats were bathed in either CO 2 -enriched water (CO 2 content 1200 mg/L) or tap water, both at 37 °C, for 10 min daily over 4 weeks. Proliferation activity was assessed by Ki67 immunohistochemistry of the epidermis of the abdomen. The capillary density was assessed by immunodetection of isolectin-positive cells. Using cryo-fixed abdominal skin epidermis, follicle cells and stroma tissue containing capillaries were separately isolated by means of laser microdissection and subjected to proteomic analysis using label-free technique. Differentially expressed proteins were validated by immunohistochemistry.Proliferation activity of keratinocytes was not significantly different in the epidermis after bathing in CO 2 -enriched water, and also, capillary density did not change. Proteomic analysis revealed up to 36 significantly regulated proteins in the analyzed tissue. Based on the best expression profiles, ten proteins were selected for immunohistochemical validation. Only one protein, far upstream element binding protein 2 (FUBP2), was similarly downregulated in the epidermis after bathing in CO 2 -enriched water with both techniques. Low FUBP2 expression was associated with low c-Myc immune-expression in keratinocytes.Long-term bathing in CO 2 -enriched water showed a cellular protein response of epithelial cells in the epidermis which was detectable by two different methods. However, differences in proliferation activity or capillary density were not detected in the normal skin.

Skin fluorescence model based on the Monte Carlo technique

NASA Astrophysics Data System (ADS)

Churmakov, Dmitry Y.; Meglinski, Igor V.; Piletsky, Sergey A.; Greenhalgh, Douglas A.

2003-10-01

The novel Monte Carlo technique of simulation of spatial fluorescence distribution within the human skin is presented. The computational model of skin takes into account spatial distribution of fluorophores following the collagen fibers packing, whereas in epidermis and stratum corneum the distribution of fluorophores assumed to be homogeneous. The results of simulation suggest that distribution of auto-fluorescence is significantly suppressed in the NIR spectral region, while fluorescence of sensor layer embedded in epidermis is localized at the adjusted depth. The model is also able to simulate the skin fluorescence spectra.

Hairless controls hair fate decision via Wnt/β-catenin signaling.

PubMed

Zhu, Kuicheng; Xu, Cunshuan; Liu, Mengduan; Zhang, Jintao

2017-09-23

The hairless (Hr) gene plays a central role in the hair cycle, considering that mutations in the gene result in hair loss with the exception of a few vibrissae after the first hair growth cycle in both mice and humans. This study examinedthe uncommon phenotype and using microarray analyses and functional studies, we found that β-catenin was mediated by Hr. Progenitor keratinocytes from the bulge region differentiate into both epidermis and sebaceous glands, and fail to adopt the hair keratinocytes fate in the mutant scalp, due to the decreased Wnt/β-catenin signaling in the absence of the hairless protein. This may be attributed to the dysfunction of normal epithelial-mesenchymal interactions in the hair follicle (HF). Copyright © 2017 Elsevier Inc. All rights reserved.

Calreticulin Enhances Porcine Wound Repair by Diverse Biological Effects

PubMed Central

Nanney, Lillian B.; Woodrell, Christopher D.; Greives, Mathew R.; Cardwell, Nancy L.; Pollins, Alonda C.; Bancroft, Tara A.; Chesser, Adrianne; Michalak, Marek; Rahman, Mohammad; Siebert, John W.; Gold, Leslie I.

2008-01-01

Extracellular functions of the endoplasmic reticulum chaperone protein calreticulin (CRT) are emerging. Here we show novel roles for exogenous CRT in both cutaneous wound healing and diverse processes associated with repair. Compared with platelet-derived growth factor-BB-treated controls, topical application of CRT to porcine excisional wounds enhanced the rate of wound re-epithelialization. In both normal and steroid-impaired pigs, CRT increased granulation tissue formation. Immunohistochemical analyses of the wounds 5 and 10 days after injury revealed marked up-regulation of transforming growth factor-β3 (a key regulator of wound healing), a threefold increase in macrophage influx, and an increase in the cellular proliferation of basal keratinocytes of the new epidermis and of cells of the neodermis. In vitro studies confirmed that CRT induced a greater than twofold increase in the cellular proliferation of primary human keratinocytes, fibroblasts, and microvascular endothelial cells (with 100 pg/ml, 100 ng/ml, and 1.0 pg/ml, respectively). Moreover, using a scratch plate assay, CRT maximally induced the cellular migration of keratinocytes and fibroblasts (with 10 pg/ml and 1 ng/ml, respectively). In addition, CRT induced concentration-dependent migration of keratinocytes, fibroblasts macrophages, and monocytes in chamber assays. These in vitro bioactivities provide mechanistic support for the positive biological effects of CRT observed on both the epidermis and dermis of wounds in vivo, underscoring a significant role for CRT in the repair of cutaneous wounds. PMID:18753412

In vitro percutaneous absorption and metabolism of Bisphenol A (BPA) through fresh human skin.

PubMed

Toner, Frank; Allan, Graham; Dimond, Stephen S; Waechter, John M; Beyer, Dieter

2018-03-01

Bisphenol A (BPA) is a high production volume compound. It is mainly used as a monomer to make polymers for various applications including food-contact materials. The primary route of exposure to BPA in the general population is through oral intake (EFSA 2015) however, other potential sources of exposure have also been identified, such as dermal contact. In the present study, the percutaneous absorption through human skin has been investigated in an in vitro study according to OECD TG 428 (Skin Absorption: In Vitro Method). In order to investigate potential dermal BPA metabolism during absorption, radiolabelled BPA was applied to fresh, metabolically competent, human skin samples (ring labelled 14 C BPA concentrations tested were 2.4, 12, 60 and 300mg/L). Measured as total radioactivity the mean absorbed dose (receptor compartment) ranged from 1.7-3.6% of the applied doses and the dermal delivery (epidermis+dermis+receptor compartment), sometimes also named bioavailable dose was 16-20% of the applied doses, with the majority of the radioactivity associated with epidermis compared to dermis and receptor fluid. No metabolism was observed in any of the epidermis samples; however some metabolism was observed in dermis and receptor fluid samples with formation of BPA-glucuronide and BPA-sulfate, and some polar metabolites. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Skin age testing criteria: characterization of human skin structures by 500 MHz MRI multiple contrast and image processing.

PubMed

Sharma, Rakesh

2010-07-21

Ex vivo magnetic resonance microimaging (MRM) image characteristics are reported in human skin samples in different age groups. Human excised skin samples were imaged using a custom coil placed inside a 500 MHz NMR imager for high-resolution microimaging. Skin MRI images were processed for characterization of different skin structures. Contiguous cross-sectional T1-weighted 3D spin echo MRI, T2-weighted 3D spin echo MRI and proton density images were compared with skin histopathology and NMR peaks. In all skin specimens, epidermis and dermis thickening and hair follicle size were measured using MRM. Optimized parameters TE and TR and multicontrast enhancement generated better MRI visibility of different skin components. Within high MR signal regions near to the custom coil, MRI images with short echo time were comparable with digitized histological sections for skin structures of the epidermis, dermis and hair follicles in 6 (67%) of the nine specimens. Skin % tissue composition, measurement of the epidermis, dermis, sebaceous gland and hair follicle size, and skin NMR peaks were signatures of skin type. The image processing determined the dimensionality of skin tissue components and skin typing. The ex vivo MRI images and histopathology of the skin may be used to measure the skin structure and skin NMR peaks with image processing may be a tool for determining skin typing and skin composition.

Skin age testing criteria: characterization of human skin structures by 500 MHz MRI multiple contrast and image processing

NASA Astrophysics Data System (ADS)

Sharma, Rakesh

2010-07-01

Ex vivo magnetic resonance microimaging (MRM) image characteristics are reported in human skin samples in different age groups. Human excised skin samples were imaged using a custom coil placed inside a 500 MHz NMR imager for high-resolution microimaging. Skin MRI images were processed for characterization of different skin structures. Contiguous cross-sectional T1-weighted 3D spin echo MRI, T2-weighted 3D spin echo MRI and proton density images were compared with skin histopathology and NMR peaks. In all skin specimens, epidermis and dermis thickening and hair follicle size were measured using MRM. Optimized parameters TE and TR and multicontrast enhancement generated better MRI visibility of different skin components. Within high MR signal regions near to the custom coil, MRI images with short echo time were comparable with digitized histological sections for skin structures of the epidermis, dermis and hair follicles in 6 (67%) of the nine specimens. Skin % tissue composition, measurement of the epidermis, dermis, sebaceous gland and hair follicle size, and skin NMR peaks were signatures of skin type. The image processing determined the dimensionality of skin tissue components and skin typing. The ex vivo MRI images and histopathology of the skin may be used to measure the skin structure and skin NMR peaks with image processing may be a tool for determining skin typing and skin composition.

Skin corrosion test: a comparison between reconstructed human epidermis and full thickness skin models.

PubMed

Catarino, Carolina Motter; do Nascimento Pedrosa, Tatiana; Pennacchi, Paula Comune; de Assis, Silvia Romano; Gimenes, Fabrícia; Consolaro, Márcia Edilaine Lopes; de Moraes Barros, Silvia Berlanga; Maria-Engler, Silvya Stuchi

2018-04-01

Currently, there is a strong global trend towards the development of in vitro models to replace the use of animals in safety evaluation tests. Reconstructed Human Epidermis (RHE) models have been employed as an alternative method to animal testing of skin corrosion and irritation potential of chemical compounds. However, the consequences of an absence of the dermal compartment in these models should be considered since the cross-talk between fibroblasts and keratinocytes is fundamental for promoting proper epidermal stratification, homeostasis, inflammatory response and wound healing. In this study, we compare in-house developed models of Reconstructed Human Epidermis (i.e. USP-RHE) and full thickness skin (i.e. USP-FTS) regarding their response when submitted to skin corrosion assays, based on Guideline 431 (OECD). The results show that both models correctly classified the four substances tested (2-phenylethyl bromide, benzylacetone, lactic acid, octanoic acid) as corrosive or non-corrosive. Furthermore, we have demonstrated higher cell viability of the USP-FTS model compared to the USP-RHE model, a sign of its improved barrier function, following the exposure to the substances test on the corrosion assay. This emphasizes the importance of employing in vitro models that are more physiologically relevant and that better mimic the in vivo situation for the toxicological screening of substances. Copyright © 2018 Elsevier B.V. All rights reserved.

In vivo multiphoton imaging of human skin: assessment of topical corticosteroid-induced epidermis atrophy and depigmentation

NASA Astrophysics Data System (ADS)

Ait El Madani, Hassan; Tancrède-Bohin, Emmanuelle; Bensussan, Armand; Colonna, Anne; Dupuy, Alain; Bagot, Martine; Pena, Ana-Maria

2012-02-01

Multiphoton microscopy has emerged in the past decade as a promising tool for noninvasive skin imaging. Our aim was to evaluate the potential of multiphoton microscopy to detect topical corticosteroids side effects within the epidermis and to provide new insights into their dynamics. Healthy volunteers were topically treated with clobetasol propionate on a small region of their forearms under overnight occlusion for three weeks. The treated region of each patient was investigated at D0, D7, D15, D22 (end of the treatment), and D60. Our study shows that multiphoton microscopy allows for the detection of corticoid-induced epidermis modifications: thinning of stratum corneum compactum and epidermis, decrease of keratinocytes size, and changes in their morphology from D7 to D22. We also show that multiphoton microscopy enables in vivo three-dimensional (3-D) quantitative assessment of melanin content. We observe that melanin density decreases during treatment and almost completely disappears at D22. Moreover, these alterations are reversible as they are no longer present at D60. Our study demonstrates that multiphoton microscopy is a convenient and powerful tool for noninvasive 3-D dynamical studies of skin integrity and pigmentation.

Immunohistochemical distribution of Ki67 in epidermis of thick glabrous skin of human digits.

PubMed

Petrovic, Aleksandar; Petrovic, Vladimir; Milojkovic, Bobana; Nikolic, Ivan; Jovanovic, Dragan; Antovic, Aleksandra; Milic, Miroslav

2018-01-01

The glabrous skin on the flexor sides of hands and feet, compared to other integument regions, has thicker epidermis and more complex pattern of epidermal ridges, wherefore in microscopy is denominated as thick skin. The epidermis of this skin type has individually unique and permanent superficial patterns, called dermatoglyphics, which are maintained by regenerative potential of deep epidermal rete ridges, that interdigitate with adjacent dermis. Using light microscopy, we analyzed cadaveric big toes thick skin samples, described histology of deep epidermal ridges (intermediate, limiting, and transverse), and quantitatively evidenced their pattern of proliferation by immunohistochemical assessment of Ki67. Immunohistochemical distribution of Ki67 was confined to basal and suprabasal layers, with pattern of distribution specific for intermediate, limiting and transverse ridges that gradually transform within epidermal height. Deep epidermal ridges, interdigitating with dermal papillae, participate in construction of intricate epidermal base, whose possible role in epidermal regeneration was also discussed. Having a prominent morphology, this type of epidermis offers the best morphological insight in complexities of skin organization, and its understanding could challenge and improve currently accepted models of epidermal organization.

Heparin inhibits melanosome uptake and inflammatory response coupled with phagocytosis through blocking PI3k/Akt and MEK/ERK signaling pathways in human epidermal keratinocytes.

PubMed

Makino-Okamura, Chieko; Niki, Yoko; Takeuchi, Seiji; Nishigori, Chikako; Declercq, Lieve; Yaroch, Daniel B; Saito, Naoaki

2014-11-01

To gain insight for the role of mast cell-produced heparin in the regulation of epidermal homeostasis and skin pigmentation, we have investigated the effect of heparin on melanosome uptake and proinflammatory responses in normal human epidermal keratinocytes (NHEKs). We quantified phagocytic activity of NHEKs with uptake of melanosomes or fluorescent microspheres. Heparin exhibited the inhibitory effect on keratinocyte phagocytosis through blocking PI3k/Akt and MEK/ERK signaling pathways. In fact, the heparin-treated NHEKs showed impaired activation of Akt and ERK during phagocytosis, whereas PI3k and MEK inhibitors significantly suppressed melanosome uptake by NHEKs. In addition, the inflammation marker cycloxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2 ) production were induced during phagocytosis, while these effects were downregulated in the presence of heparin. Our observations suggest that heparin may play an antiphagocytic and anti-inflammation role in epidermis of human skin. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Prediction of percutaneous absorption in human using three-dimensional human cultured epidermis LabCyte EPI-MODEL.

PubMed

Hikima, Tomohiro; Kaneda, Noriaki; Matsuo, Kyouhei; Tojo, Kakuji

2012-01-01

The objective of this study is to establish a relationship of the skin penetration parameters between the three-dimensional cultured human epidermis LabCyte EPI-MODEL (LabCyte) and hairless mouse (HLM) skin penetration in vitro and to predict the skin penetration and plasma concentration profile in human. The skin penetration experiments through LabCyte and HLM skin were investigated using 19 drugs that have a different molecular weight and lipophilicity. The penetration flux for LabCyte reached 30 times larger at maximum than that for HLM skin. The human data can be estimated from the in silico approach with the diffusion coefficient (D), the partition coefficient (K) and the skin surface concentration (C) of drugs by assuming the bi-layer skin model for both LabCyte and HLM skin. The human skin penetration of β-estradiol, prednisolone, testosterone and ethynylestradiol was well agreed between the simulated profiles and in vitro experimental data. Plasma concentration profiles of β-estradiol in human were also simulated and well agreed with the clinical data. The present alternative method may decrease human or animal skin experiment for in vitro skin penetration.

S100A8/A9 Stimulates Keratinocyte Proliferation in the Development of Squamous Cell Carcinoma of the Skin via the Receptor for Advanced Glycation-End Products

PubMed Central

Iotzova-Weiss, Guergana; Dziunycz, Piotr J.; Freiberger, Sandra N.; Läuchli, Severin; Hafner, Jürg; Vogl, Thomas; French, Lars E.; Hofbauer, Günther F. L.

2015-01-01

Squamous cell carcinoma (SCC) is the most common neoplasm in organ transplant recipients (OTR) on long-term immunosuppression and occurs 60- to 100-fold more frequently than in the general population. Here, we present the receptor for advanced glycation end products (RAGE) and S100A8/A9 as important factors driving normal and tumor keratinocyte proliferation. RAGE and S100A8/A9 were transcriptionally upregulated in SCC compared to normal epidermis, as well as in OTR compared to immunocompetent patients (IC) with SCC. The proliferation of normal and SCC keratinocytes was induced by exposure to exogenous S100A8/A9 which in turn was abolished by blocking of RAGE. The migratory activities of normal and SCC keratinocytes were also increased upon exposure to S100A8/A9. We demonstrated that exogenous S100A8/A9 induces phosphorylation of p38 and SAPK/JNK followed by activation of ERK1/2. We hypothesize that RAGE and S100A8/A9 contribute to the development of human SCC by modulating keratinocyte growth and migration. These processes do not seem to be impaired by profound drug-mediated immunosuppression in OTR. PMID:25811984

Phosphodiesterase 4B plays a role in benzophenone-3-induced phototoxicity in normal human keratinocytes.

PubMed

Kim, Hyoung-June; Lee, Eunyoung; Lee, Moonyoung; Ahn, Sungjin; Kim, Jungmin; Liu, Jingjing; Jin, Sun Hee; Ha, Jaehyoun; Bae, Il Hong; Lee, Tae Ryong; Noh, Minsoo

2018-01-01

Benzophenone-3 (BP-3), which is extensively used in organic sunscreen, has phototoxic potential in human skin. Phosphodiesterase 4B (PDE4B) has a well-established role in inflammatory responses in immune cells. Currently, it is unknown if PDE4B is associated with BP-3-induced phototoxicity in normal human keratinocytes (NHKs). We found that BP-3 significantly increased PDE4B expression in ultraviolet B (UVB)-irradiated NHKs. Notably, BP-8, a sunscreen agent that shares the 2-hydroxy-4-methoxyphenyl methanone moiety with BP-3, also upregulated PDE4B expression in NHKs. Upon UVB irradiation, BP-3 upregulated the expression of pro-inflammatory factors, such as prostaglandin endoperoxide synthase 2, tumor necrosis factor α, interleukin 8, and S100A7, and downregulated the level of cornified envelope associated proteins, which are important in the development of the epidermal permeability barrier. The additive effects of UVB-activated BP-3 on the expression of both pro-inflammatory mediators and cornified envelope associated proteins were antagonized by treatment with the PDE4 inhibitor rolipram. The BP-3 and UVB co-stimulation-induced PDE4B upregulation and its association with the upregulation of pro-inflammatory mediators and the downregulation of epidermal differentiation markers were confirmed in a reconstituted three dimensional human epidermis model. Therefore, PDE4B has a role in the mechanism of BP-3-induced phototoxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

AKT1 provides an essential survival signal required for differentiation and stratification of primary human keratinocytes.

PubMed

Thrash, Barry R; Menges, Craig W; Pierce, Robert H; McCance, Dennis J

2006-04-28

Keratinocyte differentiation and stratification are complex processes involving multiple signaling pathways, which convert a basal proliferative cell into an inviable rigid squame. Loss of attachment to the basement membrane triggers keratinocyte differentiation, while in other epithelial cells, detachment from the extracellular matrix leads to rapid programmed cell death or anoikis. The potential role of AKT in providing a survival signal necessary for stratification and differentiation of primary human keratinocytes was investigated. AKT activity increased during keratinocyte differentiation and was attributed to the specific activation of AKT1 and AKT2. Targeted reduction of AKT1 expression, but not AKT2, by RNA interference resulted in an abnormal epidermis in organotypic skin cultures with a thin parabasal region and a pronounced but disorganized cornified layer. This abnormal stratification was due to significant cell death in the suprabasal layers and was alleviated by caspase inhibition. Normal expression patterns of both early and late markers of keratinocyte differentiation were also disrupted, producing a poorly developed stratum corneum.

Effects of cryogen spray cooling and high radiant exposures on selective vascular injury during laser irradiation of human skin.

PubMed

Tunnell, James W; Chang, David W; Johnston, Carol; Torres, Jorge H; Patrick, Charles W; Miller, Michael J; Thomsen, Sharon L; Anvari, Bahman

2003-06-01

Increasing radiant exposure offers a means to increase treatment efficacy during laser-mediated treatment of vascular lesions, such as port-wine stains; however, excessive radiant exposure decreases selective vascular injury due to increased heat generation within the epidermis and collateral damage to perivascular collagen. To determine if cryogen spray cooling could be used to maintain selective vascular injury (ie, prevent epidermal and perivascular collagen damage) when using high radiant exposures (16-30 J/cm2). Observational study. Academic hospital and research laboratory. Twenty women with normal abdominal skin (skin phototypes I-VI). Skin was irradiated with a pulsed dye laser (wavelength = 585 nm; pulse duration = 1.5 milliseconds; 5-mm-diameter spot) using various radiant exposures (8-30 J/cm2) without and with cryogen spray cooling (50- to 300-millisecond cryogen spurts). Hematoxylin-eosin-stained histologic sections from each irradiated site were examined for the degree of epidermal damage, maximum depth of red blood cell coagulation, and percentage of vessels containing perivascular collagen coagulation. Long cryogen spurt durations (>200 milliseconds) protected the epidermis in light-skinned individuals (skin phototypes I-IV) at the highest radiant exposure (30 J/cm2); however, epidermal protection could not be achieved in dark-skinned individuals (skin phototypes V-VI) even at the lowest radiant exposure (8 J/cm2). The red blood cell coagulation depth increased with increasing radiant exposure (to >2.5 mm for skin phototypes I-IV and to approximately 1.2 mm for skin phototypes V-VI). In addition, long cryogen spurt durations (>200 milliseconds) prevented perivascular collagen coagulation in all skin types. Cryogen spurt durations much longer than those currently used in therapy (>200 milliseconds) may be clinically useful for protecting the epidermis and perivascular tissues when using high radiant exposures during cutaneous laser therapies. Additional studies are necessary to prove clinical safety of these protocols.

Fractional CO2 laser resurfacing of photoaged facial and non-facial skin: histologic and clinical results and side effects.

PubMed

Sasaki, Gordon H; Travis, Heather M; Tucker, Barbara

2009-12-01

CO(2) fractional ablation offers the potential for facial and non-facial skin resurfacing with minimal downtime and rapid recovery. The purpose of this study was (i) to document the average depths and density of adnexal structures in non-lasered facial and non-facial body skin; (ii) to determine injury in ex vivo human thigh skin with varying fractional laser modes; and (iii) to evaluate the clinical safety and efficacy of treatments. Histologies were obtained from non-lasered facial and non-facial skin from 121 patients and from 14 samples of excised lasered thigh skin. Seventy-one patients were evaluated after varying energy (mJ) and density settings by superficial ablation, deeper penetration, and combined treatment. Skin thickness and adnexal density in non-lasered skin exhibited variable ranges: epidermis (47-105 mum); papillary dermis (61-105 mum); reticular dermis (983-1986 mum); hair follicles (2-14/ HPF); sebaceous glands (2-23/HPF); sweat glands (2-7/HPF). Histological studies of samples from human thigh skin demonstrated that increased fluencies in the superficial, deep and combined mode resulted in predictable deeper levels of ablations and thermal injury. An increase in density settings results in total ablation of the epidermis. Clinical improvement of rhytids and pigmentations in facial and non-facial skin was proportional to increasing energy and density settings. Patient assessments and clinical gradings by the Wilcoxon's test of outcomes correlated with more aggressive settings. Prior knowledge of normal skin depths and adnexal densities, as well as ex vivo skin laser-injury profiles at varying fluencies and densities, improve the safety and efficiency of fractional CO(2) for photorejuvenation of facial and non-facial skin.

Confocal laser scanning microscopy to estimate nanoparticles' human skin penetration in vitro.

PubMed

Zou, Ying; Celli, Anna; Zhu, Hanjiang; Elmahdy, Akram; Cao, Yachao; Hui, Xiaoying; Maibach, Howard

2017-01-01

With rapid development of nanotechnology, there is increasing interest in nanoparticle (NP) application and its safety and efficacy on human skin. In this study, we utilized confocal laser scanning microscopy to estimate NP skin penetration. Three different-sized polystyrene NPs marked with red fluorescence were applied to human skin, and Calcium Green 5N was used as a counterstain. Dimethyl sulfoxide (DMSO) and ethanol were used as alternative vehicles for NPs. Tape stripping was utilized as a barrier-damaged skin model. Skin biopsies dosed with NPs were incubated at 4°C or 37°C for 24 hours and imaged using confocal laser scanning microscopy. NPs were localized in the stratum corneum (SC) and hair follicles without penetrating the epidermis/dermis. Barrier alteration with tape stripping and change in incubation temperature did not induce deeper penetration. DMSO enhanced NP SC penetration but ethanol did not. Except with DMSO vehicle, these hydrolyzed polystyrene NPs did not penetrate intact or barrier-damaged human "viable" epidermis. For further clinical relevance, in vivo human skin studies and more sensitive analytic chemical methodology are suggested.

Distribution of keratin and associated proteins in the epidermis of monotreme, marsupial, and placental mammals.

PubMed

Alibardi, Lorenzo; Maderson, Paul F A

2003-10-01

The expression of acidic and basic keratins, and of some keratinization marker proteins such as filaggrin, loricrin, involucrin, and trichohyalin, is known for the epidermis of only a few eutherian species. Using light and high-resolution immunocytochemistry, the presence of these proteins has been studied in two monotreme and five marsupial species and compared to that in eutherians. In both monotreme and marsupial epidermis lamellar bodies occur in the upper spinosus and granular layers. Development of the granular layer varies between species and regionally within species. There is great interspecific variation in the size (0.1-3.0 microm) of keratohyalin granules (KHGs) associated with production of orthokeratotic corneous tissues. Those skin regions lacking hairs (platypus web), or showing reduced pelage density (wombat) have, respectively, minute or indiscernible KHGs, associated with patchy, or total, parakeratosis. Ultrastructural analysis shows that monotreme and marsupial KHGs comprise irregular coarse filaments of 25-40 nm that contact keratin filaments. Except for parakeratotic tissues of platypus web, distribution of acidic and basic proteins in monotreme and marsupial epidermis as revealed by anti-keratin antibodies AE1, AE2, and AE3 resembles that of eutherian epidermis. Antibodies against human or rat filaggrins have little or no cross-reactivity with epidermal proteins of other mammals: only sparse areas of wombat and rabbit epidermis show a weak immunofluorescence in transitional cells and in the deepest corneous tissues. Of the available, eutherian-derived antibodies, that against involucrin shows no cross-reactivity with any monotreme and marsupial epidermal tissues and that against trichohyalin cross-reacts only with cells in the inner root sheath and medulla of hairs. These results suggest that if involucrin and trichohyalin are present throughout noneutherian epidermis, they may have species-specific molecular structures. By contrast, eutherian-derived anti-loricrin antibodies show a weak to intense cross-reactivity to KHGs and corneous tissues of both orthokeratotic and parakeratotic epidermis in monotremes and marsupials. High-resolution immunogold analysis of loricrin distribution in immature keratinocytes of platypus parakeratotic web epidermis identifies labeled areas of round or irregular, electron-pale granules within the denser keratohyalin component and keratin network. In the deepest mature tissues, loricrin-like labeling is diffuse throughout the cytoplasm, so that cells lack the preferential distribution of loricrin along the corneous envelope that characterizes mature eutherian keratinocytes. Thus, the irregular distribution of loricrin in platypus parakeratotic tissues more resembles that which has been described for reptilian and avian keratinocytes. These observations on the noneutherian epidermis show that a stratum granulosum is present to different degrees, even discontinuous within one tissue, so that parakeratotic and orthokeratotic areas may alternate: this might imply that parakeratotic monotreme epidermis reflects the primitive pattern of amniote alpha-keratogenesis. Absent from anamniote epidermis and all sauropsid beta-keratogenic tissues, the ubiquitous presence of a loricrin-like protein as a major component of other amniote corneous tissues suggests that this is a primitive feature of amniote alpha-keratogenesis. The apparent lack of specific regionalization of loricin near the plasma membranes of monotreme keratinocytes could be an artifactual result of the immunofluorescence technique employed, or there may be masking of the antigenicity of loricrin-like proteins once they are incorporated into the corneous envelope. Nevertheless, the mechanism of redistribution of such proteins during maturation of monotreme keratinocytes is different from, perhaps more primitive, or less specialized, than that in the epidermis of eutherian mammals. Copyright 2003 Wiley-Liss, Inc.

Re-epithelialization of cutaneous wounds in adult zebrafish combines mechanisms of wound closure in embryonic and adult mammals.

PubMed

Richardson, Rebecca; Metzger, Manuel; Knyphausen, Philipp; Ramezani, Thomas; Slanchev, Krasimir; Kraus, Christopher; Schmelzer, Elmon; Hammerschmidt, Matthias

2016-06-15

Re-epithelialization of cutaneous wounds in adult mammals takes days to complete and relies on numerous signalling cues and multiple overlapping cellular processes that take place both within the epidermis and in other participating tissues. Re-epithelialization of partial- or full-thickness skin wounds of adult zebrafish, however, is extremely rapid and largely independent of the other processes of wound healing. Live imaging after treatment with transgene-encoded or chemical inhibitors reveals that re-epithelializing keratinocytes repopulate wounds by TGF-β- and integrin-dependent lamellipodial crawling at the leading edges of the epidermal tongue. In addition, re-epithelialization requires long-range epithelial rearrangements, involving radial intercalations, flattening and directed elongation of cells - processes that are dependent on Rho kinase, JNK and, to some extent, planar cell polarity within the epidermis. These rearrangements lead to a massive recruitment of keratinocytes from the adjacent epidermis and make re-epithelialization independent of keratinocyte proliferation and the mitogenic effect of FGF signalling, which are only required after wound closure, allowing the epidermis outside the wound to re-establish its normal thickness. Together, these results demonstrate that the adult zebrafish is a valuable in vivo model for studying and visualizing the processes involved in cutaneous wound closure, facilitating the dissection of direct from indirect and motogenic from mitogenic effects of genes and molecules affecting wound re-epithelialization. © 2016. Published by The Company of Biologists Ltd.

Analysis of skin tissues spatial fluorescence distribution by the Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Y Churmakov, D.; Meglinski, I. V.; Piletsky, S. A.; Greenhalgh, D. A.

2003-07-01

A novel Monte Carlo technique of simulation of spatial fluorescence distribution within the human skin is presented. The computational model of skin takes into account the spatial distribution of fluorophores, which would arise due to the structure of collagen fibres, compared to the epidermis and stratum corneum where the distribution of fluorophores is assumed to be homogeneous. The results of simulation suggest that distribution of auto-fluorescence is significantly suppressed in the near-infrared spectral region, whereas the spatial distribution of fluorescence sources within a sensor layer embedded in the epidermis is localized at an `effective' depth.

Role of fibroblast-derived factors in the pathogenesis of melasma.

PubMed

Byun, J W; Park, I S; Choi, G S; Shin, J

2016-08-01

The hyperactive melanocytes present in melasma skin are confined to the epidermis, but epidermal ablation to treat melasma pigmentation may lead to disease recurrence and aggravation. Melanocyte function is regulated by interactions between melanocytes and neighbouring cells such as keratinocytes and fibroblasts. Because melasma skin usually shows dermal changes after exposure to sunlight, we hypothesized that sun-damaged fibroblasts might play a crucial role in the pathogenesis of melasma. In this study, the melanogenic role of primary cultured fibroblasts from human melasma skin was investigated. We explored whether primary cultured fibroblasts from melasma tissue have a melanogenic function on cultured human epidermal melanocytes and artificial skin. The cytokine profile derived from fibroblasts and their effect on the pigmented epidermal equivalents were investigated. Fibroblasts from the melasma lesion and perilesional skin increased melanogenesis in cultured human epidermal melanocytes and in artificial skin. Fibroblasts from the melasma lesion and perilesional skin secreted more nerve growth factor (NGF)-β than those in normal buttock skin, and also increased melanogenesis and the expression level of NGF-β in cultured human epidermal melanocytes and artificial skin. These results suggest that fibroblasts may play a role in melanogenesis and the pathogenesis of melasma. © 2016 British Association of Dermatologists.

Age-associated decrease in GDNF and its cognate receptor GFRα-1 protein expression in human skin.

PubMed

Adly, Mohamed A; Assaf, Hanan A; Hussein, Mahmoud Rezk Abdelwahed

2016-06-01

Glial cell line-derived neurotrophic factor (GDNF) and its cognate receptor (GFRα-1) are expressed in normal human skin. They are involved in murine hair follicle morphogenesis and cycling control. We hypothesize that 'GDNF and GFRα-1 protein expression in human skin undergoes age-associated alterations. To test our hypothesis, the expression of these proteins was examined in human skin specimens obtained from 30 healthy individuals representing three age groups: children (5-18 years), adults (19-60 years) and the elderly (61-81 years). Immunofluorescent and light microscopic immunohistologic analyses were performed using tyramide signal amplification and avidin-biotin complex staining methods respectively. GDNF mRNA expression was examined by RT-PCR analysis. GDNF mRNA and protein as well as GFRα-1 protein expressions were detected in normal human skin. We found significantly reduced epidermal expression of these proteins with ageing. In the epidermis, the expression was strong in the skin of children and declined gradually with ageing, being moderate in adults and weak in the elderly. In children and adults, the expression of both GDNF and GFRα-1 proteins was strongest in the stratum basale and decreased gradually towards the surface layers where it was completely absent in the stratum corneum. In the elderly, GDNF and GFRα-1 protein expression was confined to the stratum basale. In the dermis, both GDNF and GFRα-1 proteins had strong expressions in the fibroblasts, sweat glands, sebaceous glands, hair follicles and blood vessels regardless of the age. Thus there is a decrease in epidermal GDNF and GFRα-1 protein expression in normal human skin with ageing. Our findings suggest that the consequences of this is that GFRα-1-mediated signalling is altered during the ageing process. The clinical and therapeutic ramifications of these observations mandate further investigations. © 2016 The Authors. International Journal of Experimental Pathology © 2016 International Journal of Experimental Pathology.

Urea uptake enhances barrier function and antimicrobial defense in humans by regulating epidermal gene expression

PubMed Central

Grether-Beck, Susanne; Felsner, Ingo; Brenden, Heidi; Kohne, Zippora; Majora, Marc; Marini, Alessandra; Jaenicke, Thomas; Rodriguez-Martin, Marina; Trullas, Carles; Hupe, Melanie; Elias, Peter M.; Krutmann, Jean

2012-01-01

Urea is an endogenous metabolite, known to enhance stratum corneum hydration. Yet, topical urea anecdotally also improves permeability barrier function, and it appears to exhibit antimicrobial activity. Hence, we hypothesized that urea is not merely a passive metabolite, but a small-molecule regulator of epidermal structure and function. In 21 human volunteers, topical urea improved barrier function in parallel with enhanced antimicrobial peptide (LL-37 and β-defensin-2) expression. Urea both stimulates expression of, and is transported into keratinocytes by two urea transporters, UT-A1 and UT-A2, and by aquaporin 3, 7 and 9. Inhibitors of these urea transporters block the downstream biological effects of urea, which include increased mRNA and protein levels for: (i) transglutaminase-1, involucrin, loricrin and filaggrin; (ii) epidermal lipid synthetic enzymes, and (iii) cathelicidin/LL-37 and β-defensin-2. Finally, we explored the potential clinical utility of urea, showing that topical urea applications normalized both barrier function and antimicrobial peptide expression in a murine model of atopic dermatitis (AD). Together, these results show that urea is a small-molecule regulator of epidermal permeability barrier function and antimicrobial peptide expression after transporter uptake, followed by gene regulatory activity in normal epidermis, with potential therapeutic applications in diseased skin. PMID:22418868

Melanin Transfer in Human 3D Skin Equivalents Generated Exclusively from Induced Pluripotent Stem Cells.

PubMed

Gledhill, Karl; Guo, Zongyou; Umegaki-Arao, Noriko; Higgins, Claire A; Itoh, Munenari; Christiano, Angela M

2015-01-01

The current utility of 3D skin equivalents is limited by the fact that existing models fail to recapitulate the cellular complexity of human skin. They often contain few cell types and no appendages, in part because many cells found in the skin are difficult to isolate from intact tissue and cannot be expanded in culture. Induced pluripotent stem cells (iPSCs) present an avenue by which we can overcome this issue due to their ability to be differentiated into multiple cell types in the body and their unlimited growth potential. We previously reported generation of the first human 3D skin equivalents from iPSC-derived fibroblasts and iPSC-derived keratinocytes, demonstrating that iPSCs can provide a foundation for modeling a complex human organ such as skin. Here, we have increased the complexity of this model by including additional iPSC-derived melanocytes. Epidermal melanocytes, which are largely responsible for skin pigmentation, represent the second most numerous cell type found in normal human epidermis and as such represent a logical next addition. We report efficient melanin production from iPSC-derived melanocytes and transfer within an entirely iPSC-derived epidermal-melanin unit and generation of the first functional human 3D skin equivalents made from iPSC-derived fibroblasts, keratinocytes and melanocytes.

Effect of Light Quality on Stomatal Opening in Leaves of Xanthium strumarium L.

PubMed

Sharkey, T D; Raschke, K

1981-11-01

Flux response curves were determined at 16 wavelengths of light for the conductance for water vapor of the lower epidermis of detached leaves of Xanthium strumarium L. An action spectrum of stomatal opening resulted in which blue light (wavelengths between 430 and 460 nanometers) was nearly ten times more effective than red light (wavelengths between 630 and 680 nanometers) in producing a conductance of 15 centimoles per square meter per second. Stomata responded only slightly to green light. An action spectrum of stomatal responses to red light corresponded to that of CO(2) assimilation; the inhibitors of photosynthetic electron transport, cyanazine (2-chloro-4[1-cyano-1-methylethylamino]-6-ethylamino-s-triazine) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea, eliminated the response to red light. This indicates that light absorption by chlorophyll is the cause of stomatal sensitivity to red light. Determination of flux response curves on leaves in the normal position (upper epidermis facing the light) or in the inverted position (lower epidermis facing the light) led to the conclusion that the photoreceptors for blue as well as for red light are located on or near the surfaces of the leaves; presumably they are in the guard cells themselves.

Automatic 3D segmentation of multiphoton images: a key step for the quantification of human skin.

PubMed

Decencière, Etienne; Tancrède-Bohin, Emmanuelle; Dokládal, Petr; Koudoro, Serge; Pena, Ana-Maria; Baldeweck, Thérèse

2013-05-01

Multiphoton microscopy has emerged in the past decade as a useful noninvasive imaging technique for in vivo human skin characterization. However, it has not been used until now in evaluation clinical trials, mainly because of the lack of specific image processing tools that would allow the investigator to extract pertinent quantitative three-dimensional (3D) information from the different skin components. We propose a 3D automatic segmentation method of multiphoton images which is a key step for epidermis and dermis quantification. This method, based on the morphological watershed and graph cuts algorithms, takes into account the real shape of the skin surface and of the dermal-epidermal junction, and allows separating in 3D the epidermis and the superficial dermis. The automatic segmentation method and the associated quantitative measurements have been developed and validated on a clinical database designed for aging characterization. The segmentation achieves its goals for epidermis-dermis separation and allows quantitative measurements inside the different skin compartments with sufficient relevance. This study shows that multiphoton microscopy associated with specific image processing tools provides access to new quantitative measurements on the various skin components. The proposed 3D automatic segmentation method will contribute to build a powerful tool for characterizing human skin condition. To our knowledge, this is the first 3D approach to the segmentation and quantification of these original images. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

Topical Gene Electrotransfer to the Epidermis of Hairless Guinea Pig by Non-Invasive Multielectrode Array

PubMed Central

Guo, Siqi; Israel, Annelise L.; Basu, Gaurav; Donate, Amy; Heller, Richard

2013-01-01

Topical gene delivery to the epidermis has the potential to be an effective therapy for skin disorders, cutaneous cancers, vaccinations and systemic metabolic diseases. Previously, we reported on a non-invasive multielectrode array (MEA) that efficiently delivered plasmid DNA and enhanced expression to the skin of several animal models by in vivo gene electrotransfer. Here, we characterized plasmid DNA delivery with the MEA in a hairless guinea pig model, which has a similar histology and structure to human skin. Significant elevation of gene expression up to 4 logs was achieved with intradermal DNA administration followed by topical non-invasive skin gene electrotransfer. This delivery produced gene expression in the skin of hairless guinea pig up to 12 to 15 days. Gene expression was observed exclusively in the epidermis. Skin gene electrotransfer with the MEA resulted in only minimal and mild skin changes. A low level of human Factor IX was detected in the plasma of hairless guinea pig after gene electrotransfer with the MEA, although a significant increase of Factor IX was obtained in the skin of animals. These results suggest gene electrotransfer with the MEA can be a safe, efficient, non-invasive skin delivery method for skin disorders, vaccinations and potential systemic diseases where low levels of gene products are sufficient. PMID:24015305

Fluorescence fibre-optic confocal microscopy of skin in vivo: microscope and fluorophores.

PubMed

Suihko, Christian; Swindle, Lucinda D; Thomas, Steven G; Serup, Jørgen

2005-11-01

Fibre-optic confocal imaging in vivo is a new approach in the assessment of human skin. The objective is to describe a novel instrument and its operation and use in combination with fluorophores. The Stratum is a fibre-optic fluorescence confocal microscope especially developed for the study of skin and mucous membranes. The system is flexible and any body site can be studied with a hand-held scanner. The light source is a 488 nm argon ion laser. Horizontal (en face) images of the epidermis and outer dermis are produced with cellular resolution. Magnification is approximately 1000 x . Fluorescein sodium is routinely used as fluorophore (intradermal injection or application to the skin surface). This fluorophore is safe for human use in vivo, but other substances (rhodamine B, Acridine Orange, green fluorescent protein, curcumin) have also been studied. The instrument produces sharp images of epidermal cell layers from the epidermal surface to the sub-papillary dermis, with sub-cellular resolution. The scanner is flexible in use. The technique of intradermal fluorophore injection requires some skill. We consider this fibre-optic instrument a potentially important tool in skin research for non-invasive optical biopsy of primarily the epidermis. Present use is focussed on research applications, where the fluorophore distribution in the skin may illustrate morphological changes in the epidermis.

Infrared spectroscopy in biomedical diagnostics

NASA Astrophysics Data System (ADS)

Afanasyeva, Natalia I.; Kolyakov, Sergei F.; Letokhov, Vladilen S.; Artioushenko, Vjacheslav G.; Golovkina, Viktoriya N.

1998-01-01

Fiberoptic evanescent wave Fourier transform infrared (FEW- FTIR) spectroscopy using fiberoptic sensors operated in the attenuated total reflection (ATR) regime in the middle infrared (IR) region of the spectrum (850 - 1850 cm-1) has recently found application in the diagnostics of tissues. The method is suitable for noninvasive and rapid (seconds) direct measurements of the spectra of normal and pathological tissues in vitro, ex vivo and in vivo. The aim of our studies is the express testing of various tumor tissues at the early stages of their development. The method is expected to be further developed for endoscopic and biopsy applications. We measured in vivo the skin normal and malignant tissues on surface (directly on patients) in various cases of basaloma, melanoma and nevus. The experiments were performed in the operating room for measurements of skin in the depth (under/in the layers of epidermis), human breast, stomach, lung, kidney tissues. The breast and skin tissues at different stages of tumor or cancer were distinguished very clearly in spectra of amide, side cyclic and noncyclic hydrogen bonded fragments of amino acid residuals, phosphate groups and sugars. Computer monitoring is being developed for diagnostics.

Actin organization and endocytic trafficking are controlled by a network linking NIMA-related kinases to the CDC-42-SID-3/ACK1 pathway

PubMed Central

Bernazzani, Sarina M.

2018-01-01

Molting is an essential process in the nematode Caenorhabditis elegans during which the epidermal apical extracellular matrix, termed the cuticle, is detached and replaced at each larval stage. The conserved NIMA-related kinases NEKL-2/NEK8/NEK9 and NEKL-3/NEK6/NEK7, together with their ankyrin repeat partners, MLT-2/ANKS6, MLT-3/ANKS3, and MLT-4/INVS, are essential for normal molting. In nekl and mlt mutants, the old larval cuticle fails to be completely shed, leading to entrapment and growth arrest. To better understand the molecular and cellular functions of NEKLs during molting, we isolated genetic suppressors of nekl molting-defective mutants. Using two independent approaches, we identified CDC-42, a conserved Rho-family GTPase, and its effector protein kinase, SID-3/ACK1. Notably, CDC42 and ACK1 regulate actin dynamics in mammals, and actin reorganization within the worm epidermis has been proposed to be important for the molting process. Inhibition of NEKL–MLT activities led to strong defects in the distribution of actin and failure to form molting-specific apical actin bundles. Importantly, this phenotype was reverted following cdc-42 or sid-3 inhibition. In addition, repression of CDC-42 or SID-3 also suppressed nekl-associated defects in trafficking, a process that requires actin assembly and disassembly. Expression analyses indicated that components of the NEKL–MLT network colocalize with both actin and CDC-42 in specific regions of the epidermis. Moreover, NEKL–MLT components were required for the normal subcellular localization of CDC-42 in the epidermis as well as wild-type levels of CDC-42 activation. Taken together, our findings indicate that the NEKL–MLT network regulates actin through CDC-42 and its effector SID-3. Interestingly, we also observed that downregulation of CDC-42 in a wild-type background leads to molting defects, suggesting that there is a fine balance between NEKL–MLT and CDC-42–SID-3 activities in the epidermis. PMID:29608564

Actin organization and endocytic trafficking are controlled by a network linking NIMA-related kinases to the CDC-42-SID-3/ACK1 pathway.

PubMed

Lažetić, Vladimir; Joseph, Braveen B; Bernazzani, Sarina M; Fay, David S

2018-04-01

Molting is an essential process in the nematode Caenorhabditis elegans during which the epidermal apical extracellular matrix, termed the cuticle, is detached and replaced at each larval stage. The conserved NIMA-related kinases NEKL-2/NEK8/NEK9 and NEKL-3/NEK6/NEK7, together with their ankyrin repeat partners, MLT-2/ANKS6, MLT-3/ANKS3, and MLT-4/INVS, are essential for normal molting. In nekl and mlt mutants, the old larval cuticle fails to be completely shed, leading to entrapment and growth arrest. To better understand the molecular and cellular functions of NEKLs during molting, we isolated genetic suppressors of nekl molting-defective mutants. Using two independent approaches, we identified CDC-42, a conserved Rho-family GTPase, and its effector protein kinase, SID-3/ACK1. Notably, CDC42 and ACK1 regulate actin dynamics in mammals, and actin reorganization within the worm epidermis has been proposed to be important for the molting process. Inhibition of NEKL-MLT activities led to strong defects in the distribution of actin and failure to form molting-specific apical actin bundles. Importantly, this phenotype was reverted following cdc-42 or sid-3 inhibition. In addition, repression of CDC-42 or SID-3 also suppressed nekl-associated defects in trafficking, a process that requires actin assembly and disassembly. Expression analyses indicated that components of the NEKL-MLT network colocalize with both actin and CDC-42 in specific regions of the epidermis. Moreover, NEKL-MLT components were required for the normal subcellular localization of CDC-42 in the epidermis as well as wild-type levels of CDC-42 activation. Taken together, our findings indicate that the NEKL-MLT network regulates actin through CDC-42 and its effector SID-3. Interestingly, we also observed that downregulation of CDC-42 in a wild-type background leads to molting defects, suggesting that there is a fine balance between NEKL-MLT and CDC-42-SID-3 activities in the epidermis.

Abnormalities in the basement membrane structure promote basal keratinocytes in the epidermis of hypertrophic scars to adopt a proliferative phenotype.

PubMed

Yang, Shaowei; Sun, Yexiao; Geng, Zhijun; Ma, Kui; Sun, Xiaoyan; Fu, Xiaobing

2016-05-01

The majority of studies on scar formation have mainly focused on the dermis and little is known of the involvement of the epidermis. Previous research has demonstrated that the scar tissue-derived keratinocytes are different from normal cells at both the genetic and cell biological levels; however, the mechanisms responsible for the fundamental abnormalities in keratinocytes during scar development remain elusive. For this purpose, in this study, we used normal, wound edge and hypertrophic scar tissue to examine the morphological changes which occur during epidermal regeneration as part of the wound healing process and found that the histological structure of hypertrophic scar tissues differed from that of normal skin, with a significant increase in epidermal thickness. Notably, staining of the basement membrane (BM) appeared to be absent in the scar tissues. Moreover, immunofluorescence staining for cytokeratin (CK)10, CK14, CK5, CK19 and integrin-β1 indicated the differential expression of cell markers in the epidermal keratinocytes among the normal, wound edge and hypertrophic scar tissues, which corresponded with the altered BM structures. By using a panel of proteins associated with BM components, we validated our hypothesis that the BM plays a significant role in regulating the cell fate decision of epidermal keratinocytes during skin wound healing. Alterations in the structure of the BM promote basal keratinocytes to adopt a proliferative phenotype both in vivo and in vitro.

Abnormalities in the basement membrane structure promote basal keratinocytes in the epidermis of hypertrophic scars to adopt a proliferative phenotype

PubMed Central

YANG, SHAOWEI; SUN, YEXIAO; GENG, ZHIJUN; MA, KUI; SUN, XIAOYAN; FU, XIAOBING

2016-01-01

The majority of studies on scar formation have mainly focused on the dermis and little is known of the involvement of the epidermis. Previous research has demonstrated that the scar tissue-derived keratinocytes are different from normal cells at both the genetic and cell biological levels; however, the mechanisms responsible for the fundamental abnormalities in keratinocytes during scar development remain elusive. For this purpose, in this study, we used normal, wound edge and hypertrophic scar tissue to examine the morphological changes which occur during epidermal regeneration as part of the wound healing process and found that the histological structure of hypertrophic scar tissues differed from that of normal skin, with a significant increase in epidermal thickness. Notably, staining of the basement membrane (BM) appeared to be absent in the scar tissues. Moreover, immunofluorescence staining for cytokeratin (CK)10, CK14, CK5, CK19 and integrin-β1 indicated the differential expression of cell markers in the epidermal keratinocytes among the normal, wound edge and hypertrophic scar tissues, which corresponded with the altered BM structures. By using a panel of proteins associated with BM components, we validated our hypothesis that the BM plays a significant role in regulating the cell fate decision of epidermal keratinocytes during skin wound healing. Alterations in the structure of the BM promote basal keratinocytes to adopt a proliferative phenotype both in vivo and in vitro. PMID:26986690

Mu-opiate receptor and Beta-endorphin expression in nerve endings and keratinocytes in human skin.

PubMed

Bigliardi-Qi, M; Sumanovski, L T; Büchner, S; Rufli, T; Bigliardi, P L

2004-01-01

We have previously shown that human epidermal keratinocytes express a functionally active micro-opiate receptor, which adds a new dimension to the recently developed research in neuroimmunodermatology and neurogenic inflammation in skin diseases. Human keratinocytes specifically bind and also produce beta-endorphin, the endogenous micro-opiate receptor ligand. Using confocal imaging microscopy, we could now demonstrate that micro-opiate receptors are not only expressed in keratinocytes, but also on unmyelinated peripheral nerve fibers in the dermis and epidermis. Some of the peripheral nerve fibers also express the ligand beta-endorphin. The keratinocytes positive for beta-endorphin staining are clustered around the terminal ends of the unmyelinated nerve fibers. Therefore the opiate receptor system seems to be crucial in the direct communication between nerves and skin. The keratinocytes can influence the unmyelinated nerve fibers in the epidermis directly via secreting beta-endorphin. On the other hand, nerve fibers can also secrete beta-endorphin and influence the migration, differentiation and probably also the cytokine production pattern of keratinocytes.

A novel fully-humanised 3D skin equivalent to model early melanoma invasion

PubMed Central

Hill, David S; Robinson, Neil D P; Caley, Matthew P; Chen, Mei; O’Toole, Edel A; Armstrong, Jane L; Przyborski, Stefan; Lovat, Penny E

2015-01-01

Metastatic melanoma remains incurable, emphasising the acute need for improved research models to investigate the underlying biological mechanisms mediating tumour invasion and metastasis, and to develop more effective targeted therapies to improve clinical outcome. Available animal models of melanoma do not accurately reflect human disease and current in vitro human skin equivalent models incorporating melanoma cells are not fully representative of the human skin microenvironment. We have developed a robust and reproducible, fully-humanised 3D skin equivalent comprising a stratified, terminally differentiated epidermis and a dermal compartment consisting of fibroblast-generated extracellular matrix. Melanoma cells incorporated into the epidermis were able to invade through the basement membrane and into the dermis, mirroring early tumour invasion in vivo. Comparison of our novel 3D melanoma skin equivalent with melanoma in situ and metastatic melanoma indicates this model accurately recreates features of disease pathology, making it a physiologically representative model of early radial and vertical growth phase melanoma invasion. PMID:26330548

Topical dissolved oxygen penetrates skin: model and method.

PubMed

Roe, David F; Gibbins, Bruce L; Ladizinsky, Daniel A

2010-03-01

It has been commonly perceived that skin receives its oxygen supply from the internal circulation. However, recent investigations have shown that a significant amount of oxygen may enter skin from the external overlying surface. A method has been developed for measuring the transcutaneous penetration of human skin by oxygen as described herein. This method was used to determine both the depth and magnitude of penetration of skin by topically applied oxygen. An apparatus consisting of human skin samples interposed between a topical oxygen source and a fluid filled chamber that registered changes in dissolved oxygen. Viable human skin samples of variable thicknesses with and without epidermis were used to evaluate the depth and magnitude of oxygen penetration from either topical dissolved oxygen (TDO) or topical gaseous oxygen (TGO) devices. This model effectively demonstrates transcutaneous penetration of topically applied oxygen. Topically applied dissolved oxygen penetrates through >700 microm of human skin. Topically applied oxygen penetrates better though dermis than epidermis, and TDO devices deliver oxygen more effectively than TGO devices. Copyright (c) 2010 Elsevier Inc. All rights reserved.

S100A8 and S100A9 are messengers in the crosstalk between epidermis and dermis modulating a psoriatic milieu in human skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Young; Jang, Sunhyae; Min, Jeong-Ki

2012-07-13

Highlights: Black-Right-Pointing-Pointer Upregulated S100A8 and/or S100A9 in psoriasis epidermis induce cytokine production. Black-Right-Pointing-Pointer Upregulated S100A8 and/or S100A9 in psoriasis epidermis induce migration of immune cells. Black-Right-Pointing-Pointer Upregulated S100A8 and/or S100A9 in psoriasis epidermis induce angiogenesis. Black-Right-Pointing-Pointer S100A8 and/or S100A9 may play a role in the crosstalk between epidermis and dermis in psoriasis. -- Abstract: S100A8 and S100A9 are members of the S100A8 protein family that exist as homodimers and heterodimers in neutrophils, monocytes, and macrophages. Recent studies have shown the pivotal roles of S100A8 and S100A9 in the propagation of inflammation and keratinocyte proliferation in psoriasis. We found significant up-regulationmore » of S100A8 and S100A9 secretion from keratinocytes in psoriatic lesions. To mimic the in vivo secretory conditions of S100A8 and S100A9 from psoriatic epidermal keratinocytes, we used the culture medium (CM) of S100A8 and S100A8/A9 adenovirus-transduced keratinocytes to investigate the functions of S100A8 and S100A9. We detected increased levels of various pro-inflammatory cytokines in the CM, including IL-8 and TNF-{alpha}, which are involved in aggravating psoriatic skin lesions, and IL-6 and members of the CXCL family of pro-angiogenic cytokines. The CM increased immune cell migration and increased angiogenesis in human umbilical vein endothelial cells. In conclusion, we found that the upregulated production of S100A8 and S100A9 by psoriatic epidermal keratinocytes activated adjacent keratinocytes to produce several cytokines. Moreover, S100A8 and S100A9 themselves function as pro-angiogenic and chemotactic factors, generating a psoriatic milieu in skin.« less

Ultrasound-facilitated transport of silver chloride (AgCl) particles in fish skin.

PubMed

Frenkel, V; Kimmel, E; Iger, Y

2000-08-10

Electron-dense nano-particles in aqueous suspension were administered by immersion into the epidermis of fish using ultrasound in the therapeutic range. Enhanced permeability of the tissues to the particles was achieved by acoustic cavitation, which induced a controlled level of necrosis in the outer cell layers, and by non-cavitational exposures, which widened intercellular spaces of non-necrosed tissue in deeper regions of the epidermis. Both particle concentration and penetration depth were quantified using transmission electron microscopy. While cavitation-induced perforation was necessary for particles to penetrate into the tissues, non-cavitational exposures during immersions increased the particle flux towards the skin surface, as well as the diffusion rate of the particles within the epidermis and their depth of penetration. The technique described above may potentially be applied for non-stressful, mass-administration of substances into aquatic animals, as well as the relatively new field of ultrasound-facilitated delivery in moist epithelial tissues in humans.

Keratins K2 and K10 are essential for the epidermal integrity of plantar skin.

PubMed

Fischer, Heinz; Langbein, Lutz; Reichelt, Julia; Buchberger, Maria; Tschachler, Erwin; Eckhart, Leopold

2016-01-01

K1 and K2 are the main type II keratins in the suprabasal epidermis where each of them heterodimerizes with the type I keratin K10 to form intermediate filaments. In regions of the ears, tail, and soles of the mouse, only K2 is co-expressed with K10, suggesting that these keratins suffice to form a mechanically resilient cytoskeleton. To determine the effects of the suppression of both main keratins, K2 and K10, in the suprabasal plantar epidermis of the mouse. Krt2(-/-) Krt10(-/-) mice were generated by crossing Krt2(-/-) and Krt10(-/-) mice. Epidermal morphology of soles of hind-paws was examined macroscopically and histologically. Immunofluorescence analysis and quantitative PCR analysis were performed to analyze the expression of keratins in sole skin of wildtype and Krt2(-/-) Krt10(-/-) mice. Highly abundant proteins of the sole stratum corneum were determined by electrophoretic and chromatographic separation and subsequent mass spectrometry. K2 and K10 are the most prominent suprabasal keratins in normal mouse soles with the exception of the footpads where K1, K9 and K10 predominate. Mice lacking both K2 and K10 were viable and developed epidermal acanthosis and hyperkeratosis in inter-footpad epidermis of the soles. The expression of keratins K1, K9 and K16 was massively increased at the RNA and protein levels in the soles of Krt2(-/-) Krt10(-/-) mice. This study demonstrates that the loss of the main cytoskeletal components of plantar epidermis, i.e. K2 and K10, can be only partly compensated by the upregulation of other keratins. The thickening of the epidermis in the soles of Krt2(-/-) Krt10(-/-) mice may serve as a model for pathomechanistic aspects of palmoplantar keratoderma. Copyright © 2015. Published by Elsevier Ireland Ltd.

Dynamics of keratinocytes in vivo using HO labeling: a sensitive marker of epidermal proliferation state.

PubMed

Hsieh, Elaine A; Chai, Christine M; de Lumen, Benito O; Neese, Richard A; Hellerstein, Marc K

2004-09-01

A heavy water ((2)H(2)O) labeling method recently developed to measure cell proliferation in vivo is applied here to the measurement of murine epidermal cell turnover and to investigate conditions in which keratinocyte proliferation is either inhibited or stimulated. The technique is based on incorporation of (2)H(2)O into the deoxyribose moiety of deoxyribonucleotides in dividing cells. Label incorporation and die-away studies in cells isolated from C57BL/6J mouse epidermis revealed the replacement rate to be 34%-44% per wk (half-life of 1.6-2 wk). The kinetics provided evidence of a non-proliferative subpopulation of cells (10%-15% of the total) within the epidermis. Topical administration of 7,12-dimethylbenz(a)anthracene and 12-O-tetradecanoylphorbol-13-acetate for 3 wk increased epidermal cell proliferation by 55% in SENCAR mice. Topical addition of lunasin, an anti-mitotic agent from soy, decreased epidermal cell proliferation modestly though significantly (16% given alone, 9% given with carcinogens). Caloric restriction (by 33% of energy intake) for 4 wk decreased the epidermal cell proliferation rate by 45% in C57BL/6J mice. In summary, epidermal cell proliferation can be measured in vivo using (2)H(2)O labeling in normal, hyper- and hypo-proliferative conditions. Potential applications of this inherently safe method in humans might include studies of psoriasis, wound healing, chemopreventive agents, and caloric intake.

Basic Fibroblast Growth Factor Influences Epidermal Homeostasis of Living Skin Equivalents through Affecting Fibroblast Phenotypes and Functions.

PubMed

Yang, Lujun; Zhang, Dangui; Wu, Hongjuan; Xie, Sitian; Zhang, Mingjun; Zhang, Bingna; Tang, Shijie

2018-05-30

To elucidate the possible mechanisms of how basic fibroblast growth factor (bFGF) influences epidermal homeostasis in a living skin equivalent (LSE) model. Several wound healing-related growth factors were analyzed at protein and mRNA levels for dermal fibroblasts of induced alpha-smooth muscle actin (α-SMA)-positive or α-SMA-negative phenotypes. During culturing an LSE model by seeding normal human keratinocytes on a fibroblast-populated type I collagen gel, bFGF or neutralizing antibody for keratinocyte growth factor (KGF) was added to investigate its effects on fibroblast phenotypes and, subsequently, epidermal homeostasis by histology and immunohistochemistry. The α-SMA-positive phenotype of fibroblasts induced by transforming growth factor beta-1 (TGF-β1) markedly suppressed the expression of KGF and hepatocyte growth factor (HGF), and slightly upregulated vascular endothelial growth factor (VEGF) and TGF-β1 at mRNA and protein levels, compared with α-SMA-negative fibroblasts treated with bFGF. α-SMA expression of fibroblasts at the epidermal-mesenchymal junction of the LSEs was suppressed by the addition of bFGF, and a better-differentiated epidermis was presented. The abrogation of KGF from fibroblasts by the addition of the KGF neutralizing antibody disenabled the LSE culturing system to develop an epidermis. bFGF, through affecting the phenotypes and functions of fibroblasts, especially KGF expression, influenced epidermal homeostasis in an LSE model. © 2018 S. Karger AG, Basel.

Downregulation of the Sonic Hedgehog/Gli pathway transcriptional target Neogenin-1 is associated with basal cell carcinoma aggressiveness.

PubMed

Casas, Bárbara S; Adolphe, Christelle; Lois, Pablo; Navarrete, Nelson; Solís, Natalia; Bustamante, Eva; Gac, Patricio; Cabané, Patricio; Gallegos, Ivan; Wainwright, Brandon J; Palma, Verónica

2017-10-13

Basal Cell Carcinoma (BCC) is one of the most diagnosed cancers worldwide. It develops due to an unrestrained Sonic Hedgehog (SHH) signaling activity in basal cells of the skin. Certain subtypes of BCC are more aggressive than others, although the molecular basis of this phenomenon remains unknown. We have previously reported that Neogenin-1 (NEO1) is a downstream target gene of the SHH/GLI pathway in neural tissue. Given that SHH participates in epidermal homeostasis, here we analyzed the epidermal expression of NEO1 in order to identify whether it plays a role in adult epidermis or BCC. We describe the mRNA and protein expression profile of NEO1 and its ligands (Netrin-1 and RGMA) in human and mouse control epidermis and in a broad range of human BCCs. We identify in human BCC a significant positive correlation in the levels of NEO1 receptor, NTN-1 and RGMA ligands with respect to GLI1 , the main target gene of the canonical SHH pathway. Moreover, we show via cyclopamine inhibition of the SHH/GLI pathway of ex vivo cultures that NEO1 likely functions as a downstream target of SHH/GLI signaling in the skin. We also show how Neo1 expression decreases throughout BCC progression in the K14-Cre:Ptch1 lox/lox mouse model and that aggressive subtypes of human BCC exhibit lower levels of NEO1 than non-aggressive BCC samples. Taken together, these data suggest that NEO1 is a SHH/GLI target in epidermis. We propose that NEO1 may be important in tumor onset and is then down-regulated in advanced BCC or aggressive subtypes.

Downregulation of the Sonic Hedgehog/Gli pathway transcriptional target Neogenin-1 is associated with basal cell carcinoma aggressiveness

PubMed Central

Casas, Bárbara S.; Adolphe, Christelle; Lois, Pablo; Navarrete, Nelson; Solís, Natalia; Bustamante, Eva; Gac, Patricio; Cabané, Patricio; Gallegos, Ivan; Wainwright, Brandon J.; Palma, Verónica

2017-01-01

Basal Cell Carcinoma (BCC) is one of the most diagnosed cancers worldwide. It develops due to an unrestrained Sonic Hedgehog (SHH) signaling activity in basal cells of the skin. Certain subtypes of BCC are more aggressive than others, although the molecular basis of this phenomenon remains unknown. We have previously reported that Neogenin-1 (NEO1) is a downstream target gene of the SHH/GLI pathway in neural tissue. Given that SHH participates in epidermal homeostasis, here we analyzed the epidermal expression of NEO1 in order to identify whether it plays a role in adult epidermis or BCC. We describe the mRNA and protein expression profile of NEO1 and its ligands (Netrin-1 and RGMA) in human and mouse control epidermis and in a broad range of human BCCs. We identify in human BCC a significant positive correlation in the levels of NEO1 receptor, NTN-1 and RGMA ligands with respect to GLI1, the main target gene of the canonical SHH pathway. Moreover, we show via cyclopamine inhibition of the SHH/GLI pathway of ex vivo cultures that NEO1 likely functions as a downstream target of SHH/GLI signaling in the skin. We also show how Neo1 expression decreases throughout BCC progression in the K14-Cre:Ptch1lox/lox mouse model and that aggressive subtypes of human BCC exhibit lower levels of NEO1 than non-aggressive BCC samples. Taken together, these data suggest that NEO1 is a SHH/GLI target in epidermis. We propose that NEO1 may be important in tumor onset and is then down-regulated in advanced BCC or aggressive subtypes. PMID:29137400

Ectopic Atoh1 expression drives Merkel cell production in embryonic, postnatal and adult mouse epidermis.

PubMed

Ostrowski, Stephen M; Wright, Margaret C; Bolock, Alexa M; Geng, Xuehui; Maricich, Stephen M

2015-07-15

Merkel cells are mechanosensitive skin cells whose production requires the basic helix-loop-helix transcription factor Atoh1. We induced ectopic Atoh1 expression in the skin of transgenic mice to determine whether Atoh1 was sufficient to create additional Merkel cells. In embryos, ectopic Atoh1 expression drove ectopic expression of the Merkel cell marker keratin 8 (K8) throughout the epidermis. Epidermal Atoh1 induction in adolescent mice similarly drove widespread K8 expression in glabrous skin of the paws, but in the whisker pads and body skin ectopic K8+ cells were confined to hair follicles and absent from interfollicular regions. Ectopic K8+ cells acquired several characteristics of mature Merkel cells in a time frame similar to that seen during postnatal development of normal Merkel cells. Although ectopic K8+ cell numbers decreased over time, small numbers of these cells remained in deep regions of body skin hair follicles at 3 months post-induction. In adult mice, greater numbers of ectopic K8+ cells were created by Atoh1 induction during anagen versus telogen and following disruption of Notch signaling by conditional deletion of Rbpj in the epidermis. Our data demonstrate that Atoh1 expression is sufficient to produce new Merkel cells in the epidermis, that epidermal cell competency to respond to Atoh1 varies by skin location, developmental age and hair cycle stage, and that the Notch pathway plays a key role in limiting epidermal cell competency to respond to Atoh1 expression. © 2015. Published by The Company of Biologists Ltd.

Altered expression of Matrix Remodeling Associated 7 (MXRA7) in psoriatic epidermis: evidence for a protective role in the psoriasis imiquimod mouse model.

PubMed

Ning, Jinling; Shen, Ying; Wang, Ting; Wang, Mengru; Liu, Wei; Sun, Yonghu; Zhang, Furen; Chen, Lingling; Wang, Yiqiang

2018-05-21

Preliminary datamining performed with Gene Expression Omnibus datasets implied that psoriasis may involve the matrix remodeling associated 7 (MXRA7), a gene with little function information yet. To test that hypothesis, studies were performed in human samples and murine models. Immunohistochemistry in normal human skin showed that MXRA7 proteins were present across the full epidermal layer, with highest expression level detected in the basal layer. In psoriatic samples, MXRA7 proteins were absent in the basal stem cells layer while suprabasal keratinocytes stained at a higher level than in normal tissues. In an imiquimod-induced psoriasis-like disease model in mice, diseased skins manifested similar MXRA7 expression pattern and change as in human samples, and MXRA7-deficient mice developed severer psoriasis-like diseases than wild-type mice did. While levels of pro-psoriatic genes (e.g. IL17, IL22, IL23, etc) in imiquimod-stimulated MXRA7-deficient mice were higher than in wild-type mice, keratinocytes isolated from MXRA7-deficient mice showed increased proliferation upon differentiation induction in culture. These data demonstrated that MXRA7 gene might function as a negative modulator in psoriasis development when pro-psoriatic factors attack, presumably via expression alteration or redistribution of MXRA7 proteins in keratinocytes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Cationic membrane-active peptides - anticancer and antifungal activity as well as penetration into human skin.

PubMed

Do, Nhung; Weindl, Günther; Grohmann, Lisa; Salwiczek, Mario; Koksch, Beate; Korting, Hans Christian; Schäfer-Korting, Monika

2014-05-01

Cationic antimicrobial peptides are ancient natural broad-spectrum antibiotics, and several compounds also exhibit anticancer activity. However, most applications pertain to bacterial infections, and treatment for skin cancer is less frequently considered. The cytotoxicity of melittin, cecropin A, protegrin-1 and histatin 5 against squamous skin cancer cell lines and normal human keratinocytes was evaluated and compared to established drugs. The results show that melittin clearly outperforms 5-fluorouracil regarding antitumor activity. Importantly, combined melittin and 5-fluorouracil enhanced cytotoxic effects on cancer cells and reduced toxicity on normal keratinocytes. Additionally, minimum inhibitory concentrations indicate that melittin also shows superior activity against clinical and laboratory strains of Candida albicans compared to amphotericin B. To evaluate its potential for topical applications, human skin penetration of melittin was investigated ex vivo and compared to two non-toxic cell-penetrating peptides (CPPs), low molecular weight protamine (LMWP) and penetratin. The stratum corneum prevents penetration into viable epidermis over 6 h; however, the peptides gain access to the viable skin after 24 h. Inhibition of digestive enzymes during skin penetration significantly enhances the availability of intact peptide. In conclusion, melittin may represent an innovative agent for non-melanoma skin cancer and infectious skin diseases. In order to develop a drug candidate, skin absorption and proteolytic digestion by skin enzymes need to be addressed. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Spontaneous cell sorting of fibroblasts and keratinocytes creates an organotypic human skin equivalent.

PubMed

Wang, C K; Nelson, C F; Brinkman, A M; Miller, A C; Hoeffler, W K

2000-04-01

We show that an inherent ability of two distinct cell types, keratinocytes and fibroblasts, can be relied upon to accurately reconstitute full-thickness human skin including the dermal-epidermal junction by a cell-sorting mechanism. A cell slurry containing both cell types added to silicone chambers implanted on the backs of severe combined immunodeficient mice sorts out to reconstitute a clearly defined dermis and stratified epidermis within 2 wk, forming a cell-sorted skin equivalent. Immunostaining of the cell-sorted skin equivalent with human cell markers showed patterns similar to those of normal full-thickness skin. We compared the cell-sorted skin equivalent model with a composite skin model also made on severe combined immunodeficient mice. The composite grafts were constructed from partially differentiated keratinocyte sheets placed on top of a dermal equivalent constructed of devitalized dermis. Electron microscopy revealed that both models formed ample numbers of normal appearing hemidesmosomes. The cell-sorted skin equivalent model, however, had greater numbers of keratin intermediate filaments within the basal keratinocytes that connected to hemidesmosomes, and on the dermal side both collagen filaments and anchoring fibril connections to the lamina densa were more numerous compared with the composite model. Our results may provide some insight into why, in clinical applications for treating burns and other wounds, composite grafts may exhibit surface instability and blistering for up to a year following grafting, and suggest the possible usefulness of the cell-sorted skin equivalent in future grafting applications.

The DP-1 transcription factor is required for keratinocyte growth and epidermal stratification.

PubMed

Chang, Wing Y; Bryce, Dawn M; D'Souza, Sudhir J A; Dagnino, Lina

2004-12-03

The epidermis is a stratified epithelium constantly replenished through the ability of keratinocytes in its basal layer to proliferate and self-renew. The epidermis arises from a single-cell layer ectoderm during embryogenesis. Large proliferative capacity is central to ectodermal cell and basal keratinocyte function. DP-1, a heterodimeric partner of E2F transcription factors, is highly expressed in the ectoderm and all epidermal layers during embryogenesis. To investigate the role of DP-1 in epidermal morphogenesis, we inhibited DP-1 activity through exogenous expression of a dominant-negative mutant (dnDP-1). Expression of the dnDP-1 mutant interferes with binding of E2F/DP-1 heterodimers to DNA and inhibits DNA replication, as well as cyclin A mRNA and protein expression. Chromatin immunoprecipitation analysis demonstrated that the cyclin A promoter is predominantly bound in proliferating keratinocytes by complexes containing E2F-3 and E2F-4. Thus, the mechanisms of decreased expression of cyclin A in the presence of dnDP-1 seem to involve inactivation of DP-1 complexes containing E2F-3 and E2F-4. To assess the consequences on epidermal morphogenesis of inhibiting DP-1 activity, we expressed dnDP-1 in rat epithelial keratinocytes in organotypic culture and observed that DP-1 inhibition negatively affected stratification of these cells. Likewise, expression of dnDP-1 in embryonic ectoderm explants produced extensive disorganization of subsequently formed epidermal basal and suprabasal layers, interfering with normal epidermal formation. We conclude that DP-1 activity is required for normal epidermal morphogenesis and ectoderm-to-epidermis transition.

[Therapeutic effect of human mesenchymal stem cells in skin after radiation damage].

PubMed

Bensidhoum, Morad; Gobin, Stéphanie; Chapel, Alain; Lemaitre, Gilles; Bouet, Stéphan; Waksman, Gilles; Thierry, Dominique; Martin, Michèle T

2005-01-01

Over 50% of all cancer patients presently receive radiotherapy at one stage in their treatment course. Inevitably skin is one of the most frequently damaged tissue due to its localization and constant turn-over. Our present goal is to reduce radiation-induced complications in human skin through stem cell therapy, particulary in human epidermis. Mesenchymal Stem Cells (MSCs) have been shown to be multipotent cells able to engraft in many tissues after injury. Herein, we isolated human MSCs and tested their capability to improve skin wound healing after irradiation. This potential was assessed in NOD/SCID mice which received 30 Gy locally on the thigh. This dose caused within 3 weeks local epidermis necrosis which was repaired within 13 weeks. MSCs were intravenously injected in irradiated mice 24 hours after exposure. Clinical scoring throughout 6 weeks gave indications that human MSCs reduced the extent of damage and accelerated the wound healing process. We show by quantitative qPCR and histological studies the presence of human MSCs derived cells into the scar. Human MSCs homed to the damaged skin and participated to the wound healing process. These results open prospects for cellular therapy by MSCs in irradiated epithelial tissues and could be extended to the whole general field of cutaneous cicatrization, particularly after burns.

Exosomes derived from human umbilical cord blood mesenchymal stem cells stimulates rejuvenation of human skin.

PubMed

Kim, Yoon-Jin; Yoo, Sae Mi; Park, Hwan Hee; Lim, Hye Jin; Kim, Yu-Lee; Lee, Seunghee; Seo, Kwang-Won; Kang, Kyung-Sun

2017-11-18

Human umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) play an important role in cutaneous wound healing, and recent studies suggested that MSC-derived exosomes activate several signaling pathways, which are conducive in wound healing and cell growth. In this study, we investigated the roles of exosomes that are derived from USC-CM (USC-CM Exos) in cutaneous collagen synthesis and permeation. We found that USC-CM has various growth factors associated with skin rejuvenation. Our in vitro results showed that USC-CM Exos integrate in Human Dermal Fibroblasts (HDFs) and consequently promote cell migration and collagen synthesis of HDFs. Moreover, we evaluated skin permeation of USC-CM Exos by using human skin tissues. Results showed that Exo-Green labeled USC-CM Exos approached the outermost layer of the epidermis after 3 h and gradually approached the epidermis after 18 h. Moreover, increased expressions of Collagen I and Elastin were found after 3 days of treatment on human skin. The results showed that USC-CM Exos is absorbed into human skin, it promotes Collagen I and Elastin synthesis in the skin, which are essential to skin rejuvenation and shows the potential of USC-CM integration with the cosmetics or therapeutics. Copyright © 2017 Elsevier Inc. All rights reserved.

Confocal laser scanning microscopy to estimate nanoparticles’ human skin penetration in vitro

PubMed Central

Elmahdy, Akram; Cao, Yachao; Hui, Xiaoying; Maibach, Howard

2017-01-01

Objective With rapid development of nanotechnology, there is increasing interest in nanoparticle (NP) application and its safety and efficacy on human skin. In this study, we utilized confocal laser scanning microscopy to estimate NP skin penetration. Methods Three different-sized polystyrene NPs marked with red fluorescence were applied to human skin, and Calcium Green 5N was used as a counterstain. Dimethyl sulfoxide (DMSO) and ethanol were used as alternative vehicles for NPs. Tape stripping was utilized as a barrier-damaged skin model. Skin biopsies dosed with NPs were incubated at 4°C or 37°C for 24 hours and imaged using confocal laser scanning microscopy. Results NPs were localized in the stratum corneum (SC) and hair follicles without penetrating the epidermis/dermis. Barrier alteration with tape stripping and change in incubation temperature did not induce deeper penetration. DMSO enhanced NP SC penetration but ethanol did not. Conclusion Except with DMSO vehicle, these hydrolyzed polystyrene NPs did not penetrate intact or barrier-damaged human “viable” epidermis. For further clinical relevance, in vivo human skin studies and more sensitive analytic chemical methodology are suggested. PMID:29184403

Entry mechanisms of herpes simplex virus 1 into murine epidermis: involvement of nectin-1 and herpesvirus entry mediator as cellular receptors.

PubMed

Petermann, Philipp; Thier, Katharina; Rahn, Elena; Rixon, Frazer J; Bloch, Wilhelm; Özcelik, Semra; Krummenacher, Claude; Barron, Martin J; Dixon, Michael J; Scheu, Stefanie; Pfeffer, Klaus; Knebel-Mörsdorf, Dagmar

2015-01-01

Skin keratinocytes represent a primary entry site for herpes simplex virus 1 (HSV-1) in vivo. The cellular proteins nectin-1 and herpesvirus entry mediator (HVEM) act as efficient receptors for both serotypes of HSV and are sufficient for disease development mediated by HSV-2 in mice. How HSV-1 enters skin and whether both nectin-1 and HVEM are involved are not known. We addressed the impact of nectin-1 during entry of HSV-1 into murine epidermis and investigated the putative contribution of HVEM. Using ex vivo infection of murine epidermis, we showed that HSV-1 entered the basal keratinocytes of the epidermis very efficiently. In nectin-1-deficient epidermis, entry was strongly reduced. Almost no entry was observed, however, in nectin-1-deficient keratinocytes grown in culture. This observation correlated with the presence of HVEM on the keratinocyte surface in epidermis and with the lack of HVEM expression in nectin-1-deficient primary keratinocytes. Our results suggest that nectin-1 is the primary receptor in epidermis, while HVEM has a more limited role. For primary murine keratinocytes, on which nectin-1 acts as a single receptor, electron microscopy suggested that HSV-1 can enter both by direct fusion with the plasma membrane and via endocytic vesicles. Thus, we concluded that nectin-1 directs internalization into keratinocytes via alternative pathways. In summary, HSV-1 entry into epidermis was shown to strongly depend on the presence of nectin-1, but the restricted presence of HVEM can potentially replace nectin-1 as a receptor, illustrating the flexibility employed by HSV-1 to efficiently invade tissue in vivo. Herpes simplex virus (HSV) can cause a range of diseases in humans, from uncomplicated mucocutaneous lesions to life-threatening infections. The skin is one target tissue of HSV, and the question of how the virus overcomes the protective skin barrier and penetrates into the tissue to reach its receptors is still open. Previous studies analyzing entry into cells grown in vitro revealed nectin-1 and HVEM as HSV receptors. To explore the contributions of nectin-1 and HVEM to entry into a natural target tissue, we established an ex vivo infection model. Using nectin-1- or HVEM-deficient mice, we demonstrated the distinct involvement of nectin-1 and HVEM for HSV-1 entry into epidermis and characterized the internalization pathways. Such advances in understanding the involvement of receptors in tissue are essential preconditions for unraveling HSV invasion of skin, which in turn will allow the development of antiviral reagents. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Staphylococcus aureus keratinocyte invasion is mediated by integrin-linked kinase and Rac1.

PubMed

Sayedyahossein, Samar; Xu, Stacey X; Rudkouskaya, Alena; McGavin, Martin J; McCormick, John K; Dagnino, Lina

2015-02-01

Staphylococcus aureus is a major component of the skin microbiota and causes a large number of serious infections. S. aureus first interacts with epidermal keratinocytes to breach the epidermal barrier through mechanisms not fully understood. By use of primary keratinocytes from mice with epidermis-restricted Ilk gene inactivation and control integrin-linked kinase (ILK)-expressing littermates, we investigated the role of ILK in epidermal S. aureus invasion. Heat-killed, but not live, bacteria were internalized to Rab5- and Rab7-positive phagosomes, and incubation with keratinocyte growth factor increased their uptake 2.5-fold. ILK-deficient mouse keratinocytes internalized bacteria 2- to 4-fold less efficiently than normal cells. The reduced invasion by live S. aureus of ILK-deficient cells was restored in the presence of exogenous, constitutively active Rac1. Thus, Rac1 functions downstream from ILK during invasion. Further, invasion by S. aureus of Rac1-deficient cells was 2.5-fold lower than in normal cells. Paradoxically, staphylococcal cutaneous penetration of mouse skin explants with ILK-deficient epidermis was 35-fold higher than that of normal skin, indicating defects in epidermal barrier function in the absence of ILK. Thus, we identified an ILK-Rac1 pathway essential for bacterial invasion of keratinocytes, and established ILK as a key contributor to prevent invasive staphylococcal cutaneous infection. © FASEB.

White-Light Supercontinuum Laser-Based Multiple Wavelength Excitation for TCSPC-FLIM of Cutaneous Nanocarrier Uptake

NASA Astrophysics Data System (ADS)

Volz, Pierre; Brodwolf, Robert; Zoschke, Christian; Haag, Rainer; Schäfer-Korting, Monika; Alexiev, Ulrike

2018-05-01

We report here on a custom-built time-correlated single photon-counting (TCSPC)-based fluorescence lifetime imaging microscopy (FLIM) setup with a continuously tunable white-light supercontinuum laser combined with acousto-optical tunable filters (AOTF) as an excitation source for simultaneous excitation of multiple spectrally separated fluorophores. We characterized the wavelength dependence of the white-light supercontinuum laser pulse properties and demonstrated the performance of the FLIM setup, aiming to show the experimental setup in depth together with a biomedical application. We herein summarize the physical-technical parameters as well as our approach to map the skin uptake of nanocarriers using FLIM with a resolution compared to spectroscopy. As an example, we focus on the penetration study of indocarbocyanine-labeled dendritic core-multishell nanocarriers (CMS-ICC) into reconstructed human epidermis. Unique fluorescence lifetime signatures of indocarbocyanine-labeled nanocarriers indicate nanocarrier-tissue interactions within reconstructed human epidermis, bringing FLIM close to spectroscopic analysis.

Spatial constraints govern competition of mutant clones in human epidermis.

PubMed

Lynch, M D; Lynch, C N S; Craythorne, E; Liakath-Ali, K; Mallipeddi, R; Barker, J N; Watt, F M

2017-10-24

Deep sequencing can detect somatic DNA mutations in tissues permitting inference of clonal relationships. This has been applied to human epidermis, where sun exposure leads to the accumulation of mutations and an increased risk of skin cancer. However, previous studies have yielded conflicting conclusions about the relative importance of positive selection and neutral drift in clonal evolution. Here, we sequenced larger areas of skin than previously, focusing on cancer-prone skin spanning five decades of life. The mutant clones identified were too large to be accounted for solely by neutral drift. Rather, using mathematical modelling and computational lattice-based simulations, we show that observed clone size distributions can be explained by a combination of neutral drift and stochastic nucleation of mutations at the boundary of expanding mutant clones that have a competitive advantage. These findings demonstrate that spatial context and cell competition cooperate to determine the fate of a mutant stem cell.

Visualization of drug distribution of topical minocycline in human facial skin with fluorescence microscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Hermsmeier, Maiko; Sawant, Tanvee; Lac, Diana; Yamamoto, Akira; Chen, Xin; Nagavarapu, Usha; Evans, Conor L.; Chan, Kin Foong

2017-02-01

Minocycline is an antibiotic regularly prescribed to treat acne vulgaris. The only commercially available minocycline comes in an oral dosage form, which often results in systemic adverse effects. A topical minocycline composition (BPX-01) was developed to provide localized and targeted delivery to the epidermis and pilosebaceous unit where acne-related bacteria, Propionibacterium acnes (P. acnes), reside. As minocycline is a known fluorophore, fluorescence microscopy was performed to investigate its potential use in visualizing minocycline distribution within tissues. BPX-01 with various concentrations of minocycline, was applied topically to freshly excised human facial skin specimens. Spatial distribution of minocycline and its fluorescence intensity within the stratum corneum, epidermis, dermis, and pilosebaceous unit were assessed. The resulting fluorescence intensity data as a function of minocycline concentration may indicate clinically relevant therapeutic doses of topical BPX-01 needed to kill P. acnes and reduce inflammation for successful clinical outcomes.

Laser abrasion for cosmetic and medical treatment of facial actinic damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

David, L.M.; Lask, G.P.; Glassberg, E.

1989-06-01

Previous studies have shown the carbon dioxide (CO/sub 2/) laser to be effective in the treatment of actinic cheilitis. After CO/sub 2/ laser abrasion, normal skin and marked cosmetic improvement of the lip were noted. In our study, twenty-three patients were treated with CO/sub 2/ laser abrasions for cosmetic improvement of facial lines and actinic changes. Pre- and postoperative histopathologic examinations were made on two patients. Preoperative examination of specimens from actinically damaged skin showed atypical keratinocytes in the basal layer of the epidermis, with overlying dense compact orthokeratosis and parakeratosis. Abundant solar elastosis was seen in the papillary dermis.more » Postoperative histologic specimens showed a normal-appearing epidermis with fibrosis in the papillary dermis and minimal solar elastosis (about four weeks after laser treatment). At present, various modalities are available for the regeneration of the aged skin, including chemical peels and dermabrasion. Significantly fewer complications were noted with CO/sub 2/ laser abrasion than with these methods. Thus, CO/sub 2/ laser abrasion can be useful in the cosmetic and medical treatment of the aged skin. Marked clinical and histologic improvement has been demonstrated.« less

Expression of cancer-related carbonic anhydrases IX and XII in normal skin and skin neoplasms.

PubMed

Syrjänen, Leo; Luukkaala, Tiina; Leppilampi, Mari; Kallioinen, Matti; Pastorekova, Silvia; Pastorek, Jaromir; Waheed, Abdul; Sly, William S; Parkkila, Seppo; Karttunen, Tuomo

2014-09-01

Purpose of the study was to evaluate the presence of hypoxia-inducible, tumour-associated carbonic anhydrases IX and XII in normal skin and a series of cutaneous tumours. Human tumour samples were taken during surgical operations performed on 245 patients and were immunohistochemically stained. A histological score value was calculated for statistical analyses which were performed using SPSS for Windows, versions 17.0 and 20.0. In normal skin, the highest expression of CA IX was detected in hair follicles, sebaceous glands, and basal parts of epidermis. CA XII was detected in all epithelial components of skin. Both CA IX and CA XII expression levels were significantly different in epidermal, appendigeal, and melanocytic tumour categories. Both CA IX and XII showed the most intense immunostaining in epidermal tumours, whereas virtually all melanocytic tumours were devoid of CA IX and XII immunostaining. In premalignant lesions, CA IX expression significantly increased when the tumours progressed to more severe dysplasia forms. Both CA IX and XII are highly expressed in different epithelial components of skin. They are also highly expressed in epidermal tumours, in which CA IX expression levels also correlate with the dysplasia grade. Interestingly, both isozymes are absent in melanocytic tumours. © 2014 APMIS. Published by John Wiley & Sons Ltd.

In Vivo Assessment of Printed Microvasculature in a Bilayer Skin Graft to Treat Full-Thickness Wounds

PubMed Central

Yanez, Maria; Rincon, Julio; Dones, Aracely; De Maria, Carmelo; Gonzales, Raoul

2015-01-01

Chronic wounds such as diabetic foot ulcers and venous leg ulcers are common problems in people suffering from type 2 diabetes. These can cause pain, and nerve damage, eventually leading to foot or leg amputation. These types of wounds are very difficult to treat and sometimes take months or even years to heal because of many possible complications during the process. Allogeneic skin grafting has been used to improve wound healing, but the majority of grafts do not survive several days after being implanted. We have been studying the behavior of fibroblasts and keratinocytes in engineered capillary-like endothelial networks. A dermo-epidermal graft has been implanted in an athymic nude mouse model to assess the integration with the host tissue as well as the wound healing process. To build these networks into a skin graft, a modified inkjet printer was used, which allowed the deposit of human microvascular endothelial cells. Neonatal human dermal fibroblast cells and neonatal human epidermal keratinocytes were manually mixed in the collagen matrix while endothelial cells printed. A full-thickness wound was created at the top of the back of athymic nude mice and the area was covered by the bilayered graft. Mice of the different groups were followed until completion of the specified experimental time line, at which time the animals were humanely euthanized and tissue samples were collected. Wound contraction improved by up to 10% when compared with the control groups. Histological analysis showed the neoskin having similar appearance to the normal skin. Both layers, dermis and epidermis, were present with thicknesses resembling normal skin. Immunohistochemistry analysis showed favorable results proving survival of the implanted cells, and confocal images showed the human cells' location in the samples that were collocated with the bilayer printed skin graft. PMID:25051339

In vivo assessment of printed microvasculature in a bilayer skin graft to treat full-thickness wounds.

PubMed

Yanez, Maria; Rincon, Julio; Dones, Aracely; De Maria, Carmelo; Gonzales, Raoul; Boland, Thomas

2015-01-01

Chronic wounds such as diabetic foot ulcers and venous leg ulcers are common problems in people suffering from type 2 diabetes. These can cause pain, and nerve damage, eventually leading to foot or leg amputation. These types of wounds are very difficult to treat and sometimes take months or even years to heal because of many possible complications during the process. Allogeneic skin grafting has been used to improve wound healing, but the majority of grafts do not survive several days after being implanted. We have been studying the behavior of fibroblasts and keratinocytes in engineered capillary-like endothelial networks. A dermo-epidermal graft has been implanted in an athymic nude mouse model to assess the integration with the host tissue as well as the wound healing process. To build these networks into a skin graft, a modified inkjet printer was used, which allowed the deposit of human microvascular endothelial cells. Neonatal human dermal fibroblast cells and neonatal human epidermal keratinocytes were manually mixed in the collagen matrix while endothelial cells printed. A full-thickness wound was created at the top of the back of athymic nude mice and the area was covered by the bilayered graft. Mice of the different groups were followed until completion of the specified experimental time line, at which time the animals were humanely euthanized and tissue samples were collected. Wound contraction improved by up to 10% when compared with the control groups. Histological analysis showed the neoskin having similar appearance to the normal skin. Both layers, dermis and epidermis, were present with thicknesses resembling normal skin. Immunohistochemistry analysis showed favorable results proving survival of the implanted cells, and confocal images showed the human cells' location in the samples that were collocated with the bilayer printed skin graft.

Protease-activated receptor 2, a receptor involved in melanosome transfer, is upregulated in human skin by ultraviolet irradiation.

PubMed

Scott, G; Deng, A; Rodriguez-Burford, C; Seiberg, M; Han, R; Babiarz, L; Grizzle, W; Bell, W; Pentland, A

2001-12-01

Previous studies have shown that the protease-activated receptor 2 is involved in skin pigmentation through increased phagocytosis of melanosomes by keratinocytes. Ultraviolet irradiation is a potent stimulus for melanosome transfer. We show that protease-activated receptor 2 expression in human skin is upregulated by ultraviolet irradiation. Subjects with skin type I, II, or III were exposed to two or three minimal erythema doses of irradiation from a solar simulator. Biopsies were taken from nonexposed and irradiated skin 24 and 96 h after irradiation and protease-activated receptor 2 expression was detected using immunohistochemical staining. In nonirradiated skin, protease-activated receptor 2 expression was confined to keratinocytes in the lower one-third of the epidermis. After ultraviolet irradiation protease-activated receptor 2 expression was observed in keratinocytes in the upper two-thirds of the epidermis or the entire epidermis at both time points studied. Subjects with skin type I showed delayed upregulation of protease-activated receptor 2 expression, however, compared with subjects with skin types II and III. Irradiated cultured human keratinocytes showed upregulation in protease-activated receptor 2 expression as determined by immunofluorescence microscopy and Western blotting. Cell culture supernatants from irradiated keratinocytes also exhibited a dose-dependent increase in protease-activated receptor-2 cleavage activity. These results suggest an important role for protease-activated receptor-2 in pigmentation in vivo. Differences in protease-activated receptor 2 regulation in type I skin compared with skin types II and III suggest a potential mechanism for differences in tanning in subjects with different skin types.

Analysis of in vitro release through reconstructed human epidermis and synthetic membranes of multi-vitamins from cosmetic formulations.

PubMed

Gabbanini, Simone; Matera, Riccardo; Beltramini, Claudia; Minghetti, Andrea; Valgimigli, Luca

2010-08-01

A convenient method for in vitro investigation of the release of lipid- and water-soluble vitamins from cosmetic formulations was developed. The permeation of (d)-alpha-tocopherol (vitamin E), retinyl acetate (pro-vitamin A), ascorbic acid (vitamin C) and pyridoxine (vitamin B6) through SkinEthic reconstructed human epidermis (RHE), and synthetic polyethersulfone and polycarbonate membranes was studied in vitro using a Franz-type diffusion apparatus, coupled either to a spectrophotometer for continuous reading (dynamic setting) or to HPLC-DAD analysis of the receptor medium (static setting). O/W and W/O emulsions were compared with simple aqueous solutions for their kinetic of vitamins release, to evaluate the influence of the cosmetic formulation on the bioavailability of active ingredients. Results indicate that synthetic membranes offer a limited barrier to the diffusion of vitamins, but may provide information on the release ability of the formulation. Penetration was more effective when water was the external phase of the formulation, i.e. W/O emulsions were less effective in the release of vitamins than O/W emulsion or aqueous solutions. RHE (17 days old) offered a significantly higher barrier to penetration of vitamins, as expected for native human epidermis. The relative ranking in coefficient of permeability (Ps (cm/h)) was: ascorbic acid>pyridoxine>retinyl acetate>alpha-tocopherol approximately 0, the absolute values depending on the formulation. The method herein described showed to be a practical and convenient tool for the quality-control and efficacy evaluation of cosmetic formulations. Copyright (c) 2010 Elsevier B.V. All rights reserved.

NASA-approved rotary bioreactor enhances proliferation of human epidermal stem cells and supports formation of 3D epidermis-like structure.

PubMed

Lei, Xiao-hua; Ning, Li-na; Cao, Yu-jing; Liu, Shuang; Zhang, Shou-bing; Qiu, Zhi-fang; Hu, Hui-min; Zhang, Hui-shan; Liu, Shu; Duan, En-kui

2011-01-01

The skin is susceptible to different injuries and diseases. One major obstacle in skin tissue engineering is how to develop functional three-dimensional (3D) substitute for damaged skin. Previous studies have proved a 3D dynamic simulated microgravity (SMG) culture system as a "stimulatory" environment for the proliferation and differentiation of stem cells. Here, we employed the NASA-approved rotary bioreactor to investigate the proliferation and differentiation of human epidermal stem cells (hEpSCs). hEpSCs were isolated from children foreskins and enriched by collecting epidermal stem cell colonies. Cytodex-3 micro-carriers and hEpSCs were co-cultured in the rotary bioreactor and 6-well dish for 15 days. The result showed that hEpSCs cultured in rotary bioreactor exhibited enhanced proliferation and viability surpassing those cultured in static conditions. Additionally, immunostaining analysis confirmed higher percentage of ki67 positive cells in rotary bioreactor compared with the static culture. In contrast, comparing with static culture, cells in the rotary bioreactor displayed a low expression of involucrin at day 10. Histological analysis revealed that cells cultured in rotary bioreactor aggregated on the micro-carriers and formed multilayer 3D epidermis structures. In conclusion, our research suggests that NASA-approved rotary bioreactor can support the proliferation of hEpSCs and provide a strategy to form multilayer epidermis structure.

Effect of Light Quality on Stomatal Opening in Leaves of Xanthium strumarium L. 1

PubMed Central

Sharkey, Thomas D.; Raschke, Klaus

1981-01-01

Flux response curves were determined at 16 wavelengths of light for the conductance for water vapor of the lower epidermis of detached leaves of Xanthium strumarium L. An action spectrum of stomatal opening resulted in which blue light (wavelengths between 430 and 460 nanometers) was nearly ten times more effective than red light (wavelengths between 630 and 680 nanometers) in producing a conductance of 15 centimoles per square meter per second. Stomata responded only slightly to green light. An action spectrum of stomatal responses to red light corresponded to that of CO2 assimilation; the inhibitors of photosynthetic electron transport, cyanazine (2-chloro-4[1-cyano-1-methylethylamino]-6-ethylamino-s-triazine) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea, eliminated the response to red light. This indicates that light absorption by chlorophyll is the cause of stomatal sensitivity to red light. Determination of flux response curves on leaves in the normal position (upper epidermis facing the light) or in the inverted position (lower epidermis facing the light) led to the conclusion that the photoreceptors for blue as well as for red light are located on or near the surfaces of the leaves; presumably they are in the guard cells themselves. PMID:16662069

The role of the SCRAMBLED receptor-like kinase in patterning the Arabidopsis root epidermis.

PubMed

Kwak, Su-Hwan; Schiefelbein, John

2007-02-01

Cell-type patterning in the Arabidopsis root epidermis is achieved by a network of transcription factors and influenced by a position-dependent mechanism. The SCRAMBLED receptor-like kinase is required for the normal pattern to arise, but its precise role is not understood. Here we describe genetic and molecular studies to define the spatial and temporal role of SCM in epidermal patterning and its relationship to the transcriptional network. Our results suggest that SCM helps unspecified epidermal cells interpret their position in relation to the underlying cortical cells and establish distinct cell identities. Furthermore, SCM loss-of-function and overexpression analyses suggest that SCM influences cell fate through its negative transcriptional regulation of the WEREWOLF MYB gene in epidermal cells at the H position. We also find that SCM function is specifically required for patterning the post-embryonic root epidermis and not for the analogous epidermal cell-type patterning during embryogenesis or hypocotyl development. In addition, we show that two closely related SCM-like genes in Arabidopsis (SRF1 and SRF3) are not required alone or together with SCM for proper epidermal patterning. These findings help define the developmental and mechanistic role of SCM and suggest a new model for its action in root epidermal cell patterning.

In-vivo morphologic and spectroscopic investigation of Psoriasis

NASA Astrophysics Data System (ADS)

Kapsokalyvas, Dimitrios; Cicchi, Riccardo; Bruscino, Nicola; Alfieri, Domenico; Massi, Daniela; Lotti, Torello; Pavone, Francesco S.

2011-07-01

Psoriasis is an autoimmune disease of the skin characterized by hyperkeratosis, hyperproliferation of the epidermis, inflammatory cell accumulation and increased dilatation of dermal papillary blood vessels. Cases of psoriasis were investigated in vivo with optical means in order to evaluate the potential of in vivo optical biopsy. A Polarization Multispectral Dermoscope was employed for the macroscopic observation. Features such as the 'dotted' blood vessels pattern was observed with high contrast. High resolution image sections of the epidermis and the dermis were produced with a custom made Multiphoton Microscope. Imaging extended from the surface of the lesion down to the papillary dermis, at a depth of 200 μm. In the epidermis, a characteristic morphology of the stratum corneum found only in Psoriasis was revealed. Additionally, the cytoplasmic area of the cells in the stratum spinosum layer was found to be smaller than normal. In the dermis the morphological features were more pronounced, where the elongated dermal papillae dominated the papillary layer. Their length exceeds 100μm, which is a far greater value compared to that of healthy skin. These in vivo observations are consistent with the ex vivo histopathological observations, supporting both the applicability and potentiality of multispectral dermoscopy and multiphoton microscopy in the field of in vivo optical investigation and biopsy of skin.

Marking cell layers with spectinomycin provides a new tool for monitoring cell fate during leaf development.

PubMed

Pyke, K; Zubko, M K; Day, A

2000-10-01

Spectinomycin, an inhibitor of plastid protein synthesis, can be used to mark specific cell layers in the shoot meristem of Brassica napus. Pale yellow-green (YG) plants resulting from spectinomycin-treatment can be propagated indefinitely in vitro. Microscopic examination showed that YG-plants result from inactivation of plastids in the L2 and L3 layers and are composed of a pale green epidermis covering a white mesophyll layer. Epidermal cells of YG and normal green plants are similar and contain 10-20 small pale green plastids. YG plants are equivalent to periclinal chimeras with the important distinction that there is no genotypic difference between the white and green cell layers. Periclinal divisions of epidermal cells take place at all stages of leaf development to produce invaginations of green mesophyll located in sectors of widely varying sizes. A periclinal division rate of 1 in 3000-4000 anticlinal divisions for the adaxial epidermis, was 2-3-fold higher than that estimated for the abaxial epidermis. Analysis of white and green mesophyll showed that chloroplasts are essential for palisade cell differentiation and this requirement is cell-autonomous. Stable marking of cell lineages with spectinomycin is simple, rapid and reveals the requirement for functional plastids in cellular differentiation.

Wound Regeneration Deficit in Rats Correlates with Low Morphogenetic Potential and Distinct Transcriptome Profile of Epidermis.

PubMed

Guerrero-Juarez, Christian F; Astrowski, Aliaksandr A; Murad, Rabi; Dang, Christina T; Shatrova, Vera O; Astrowskaja, Aksana; Lim, Chae Ho; Ramos, Raul; Wang, Xiaojie; Liu, Yuchen; Lee, Hye-Lim; Pham, Kim T; Hsi, Tsai-Ching; Oh, Ji Won; Crocker, Daniel; Mortazavi, Ali; Ito, Mayumi; Plikus, Maksim V

2018-06-01

Large excisional wounds in mice prominently regenerate new hair follicles (HFs) and fat, yet humans are deficient for this regenerative behavior. Currently, wound-induced regeneration remains a clinically desirable, but only partially understood phenomenon. We show that large excisional wounds in rats across seven strains fail to regenerate new HFs. We compared wound transcriptomes between mice and rats at the time of scab detachment, which coincides with the onset of HF regeneration in mice. In both species, wound dermis and epidermis share core dermal and epidermal transcriptional programs, respectively, yet prominent interspecies differences exist. Compared with mice, rat epidermis expresses distinct transcriptional and epigenetic factors, markers of epidermal repair, hyperplasia, and inflammation, and lower levels of WNT signaling effectors and regulators. When recombined on the surface of excisional wounds with vibrissa dermal papillae, partial-thickness skin grafts containing distal pelage HF segments, but not interfollicular epidermis, readily regenerated new vibrissa-like HFs. Together, our findings establish rats as a nonregenerating rodent model for excisional wound healing and suggest that low epidermal competence and associated transcriptional profile may contribute to its regenerative deficiency. Future comparison between rat and mouse may lend further insight into the mechanism of wounding-induced regeneration and causes for its deficit. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Melanin Transfer in Human 3D Skin Equivalents Generated Exclusively from Induced Pluripotent Stem Cells

PubMed Central

Gledhill, Karl; Guo, Zongyou; Umegaki-Arao, Noriko; Higgins, Claire A.; Itoh, Munenari; Christiano, Angela M.

2015-01-01

The current utility of 3D skin equivalents is limited by the fact that existing models fail to recapitulate the cellular complexity of human skin. They often contain few cell types and no appendages, in part because many cells found in the skin are difficult to isolate from intact tissue and cannot be expanded in culture. Induced pluripotent stem cells (iPSCs) present an avenue by which we can overcome this issue due to their ability to be differentiated into multiple cell types in the body and their unlimited growth potential. We previously reported generation of the first human 3D skin equivalents from iPSC-derived fibroblasts and iPSC-derived keratinocytes, demonstrating that iPSCs can provide a foundation for modeling a complex human organ such as skin. Here, we have increased the complexity of this model by including additional iPSC-derived melanocytes. Epidermal melanocytes, which are largely responsible for skin pigmentation, represent the second most numerous cell type found in normal human epidermis and as such represent a logical next addition. We report efficient melanin production from iPSC-derived melanocytes and transfer within an entirely iPSC-derived epidermal-melanin unit and generation of the first functional human 3D skin equivalents made from iPSC-derived fibroblasts, keratinocytes and melanocytes. PMID:26308443

The histamine-synthesizing enzyme histidine decarboxylase is upregulated by keratinocytes in atopic skin.

PubMed

Gutowska-Owsiak, D; Greenwald, L; Watson, C; Selvakumar, T A; Wang, X; Ogg, G S

2014-10-01

Histamine is an abundant mediator accumulating in the skin of atopic patients, where it is thought to be derived from immune cells. While keratinocytes express histidine decarboxylase (HDC), levels of the enzyme in normal or diseased epidermis and factors that influence its expression in human keratinocytes are not known. To assess levels of HDC in inflammatory skin diseases and factors influencing its expression. Normal and filaggrin-insufficient human keratinocytes, organotypic epidermal models and skin samples were investigated for the expression of HDC. The effect of cytokines, bacterial and allergen stimuli exposure and functional changes in differentiation were evaluated in vitro. We detected abundant expression of the HDC protein in all models studied; expression was increased in atopic skin samples. Filaggrin-insufficient keratinocytes maintained HDC levels, but exposure of keratinocytes to thymic stromal lymphopoietin, tumour necrosis factor-α, lipopolysaccharide (LPS) and house dust mite (HDM) extract increased HDC expression in vitro. Furthermore, filaggrin expression in cultured keratinocytes increased following histamine depletion. Keratinocytes express abundant HDC protein, and the levels increase in atopic skin. LPS, HDM and cytokines, which are implicated in allergic inflammation, promote the expression of the enzyme and upregulate histamine levels in keratinocytes. Actively produced histamine influences keratinocyte differentiation, suggesting functional relevance of the axis to atopic dermatitis. The findings therefore identify a new point of therapeutic intervention. © 2014 British Association of Dermatologists.

Real-time visualization of melanin granules in normal human skin using combined multiphoton and reflectance confocal microscopy.

PubMed

Majdzadeh, Ali; Lee, Anthony M D; Wang, Hequn; Lui, Harvey; McLean, David I; Crawford, Richard I; Zloty, David; Zeng, Haishan

2015-05-01

Recent advances in biomedical optics have enabled dermal and epidermal components to be visualized at subcellular resolution and assessed noninvasively. Multiphoton microscopy (MPM) and reflectance confocal microscopy (RCM) are noninvasive imaging modalities that have demonstrated promising results in imaging skin micromorphology, and which provide complementary information regarding skin components. This study assesses whether combined MPM/RCM can visualize intracellular and extracellular melanin granules in the epidermis and dermis of normal human skin. We perform MPM and RCM imaging of in vivo and ex vivo skin in the infrared domain. The inherent three-dimensional optical sectioning capability of MPM/RCM is used to image high-contrast granular features across skin depths ranging from 50 to 90 μm. The optical images thus obtained were correlated with conventional histologic examination including melanin-specific staining of ex vivo specimens. MPM revealed highly fluorescent granular structures below the dermal-epidermal junction (DEJ) region. Histochemical staining also demonstrated melanin-containing granules that correlate well in size and location with the granular fluorescent structures observed in MPM. Furthermore, the MPM fluorescence excitation wavelength and RCM reflectance of cell culture-derived melanin were equivalent to those of the granules. This study suggests that MPM can noninvasively visualize and quantify subepidermal melanin in situ. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Human skin penetration of the major components of Australian tea tree oil applied in its pure form and as a 20% solution in vitro.

PubMed

Cross, Sheree E; Russell, Michael; Southwell, Ian; Roberts, Michael S

2008-05-01

The safety of topical application of Australian tea tree Oil (TTO) is confounded by a lack of transdermal penetration data, which adequately informs opinions and recommendations. In this study we applied TTO in its pure form and as a 20% solution in ethanol in vitro to human epidermal membranes from three different donors, mounted in horizontal Franz-type diffusion cells, using normal 'in use' dosing conditions (10 mg/cm2). In addition, we examined the effect of partially occluding the application site on the penetration of TTO components. Our data showed that only a small quantity of TTO components, 1.1-1.9% and 2-4% of the applied amount following application of a 20% TTO solution and pure TTO, respectively, penetrated into or through human epidermis. The largest TTO component penetrating the skin was terpinen-4-ol. Following partial occlusion of the application site, the penetration of terpinen-4-ol increased to approximately 7% of the applied TTO. Measurement of the rate of evaporation of tea tree oil from filter paper (7.4 mg/cm2) showed that 98% of the oil evaporated in 4 hours. Overall, it is apparent that the penetration of TTO components through human skin is limited.

Color-dilution alopecia in dogs.

PubMed

Kim, Jae Hoon; Kang, Kyung Il; Sohn, Hyun Joo; Woo, Gye Hyeong; Jean, Young Hwa; Hwang, Eui Kyung

2005-09-01

Color-dilution alopecia is a relatively uncommon hereditary skin disease seen in "Blue" and other color-diluted dogs. This syndrome is associated with a color-dilution gene. The initial clinical signs are the gradual onset of a dry, dull and poor hair coat quality. Hair shafts and hair regrowth are poor, and follicular papules may develop and progress to frank comedones. Hair loss and comedo formation are usually most severe on the trunk, especially color-diluted area on the skin. Six cases of color-dilution alopecia are reported in 3 months to 10 years old dogs. The breeds of dogs are blue Doberman Pinscher, Miniature Pinscher, Dachshund, and Schnauzer. Grossly, extensive partial hair loss was seen on the skin. Histopathologically, the epidermis is relatively normal but may be hyperplastic. Hair follicles are characterized by atrophy and distortion. Heavily clumped melanin is present in the epidermis, dermis and hair follicles.

Human eccrine sweat gland cells turn into melanin-uptaking keratinocytes in dermo-epidermal skin substitutes.

PubMed

Böttcher-Haberzeth, Sophie; Biedermann, Thomas; Pontiggia, Luca; Braziulis, Erik; Schiestl, Clemens; Hendriks, Bart; Eichhoff, Ossia M; Widmer, Daniel S; Meuli-Simmen, Claudia; Meuli, Martin; Reichmann, Ernst

2013-02-01

Recently, Biedermann et al. (2010) have demonstrated that human eccrine sweat gland cells can develop a multilayered epidermis. The question still remains whether these cells can fulfill exclusive and very specific functional properties of epidermal keratinocytes, such as the incorporation of melanin, a feature absent in sweat gland cells. We added human melanocytes to eccrine sweat gland cells to let them develop into an epidermal analog in vivo. The interaction between melanocytes and sweat gland-derived keratinocytes was investigated. The following results were gained: (1) macroscopically, a pigmentation of the substitutes was seen 2-3 weeks after transplantation; (2) we confirmed the development of a multilayered, stratified epidermis with melanocytes distributed evenly throughout the basal layer; (3) melanocytic dendrites projected to suprabasal layers; and (4) melanin was observed to be integrated into former eccrine sweat gland cells. These skin substitutes were similar or equal to skin substitutes cultured from human epidermal keratinocytes. The only differences observed were a delay in pigmentation and less melanin uptake. These data suggest that eccrine sweat gland cells can form a functional epidermal melanin unit, thereby providing striking evidence that they can assume one of the most characteristic keratinocyte properties.

Arsenic Induces p62 Expression to Form a Positive Feedback Loop with Nrf2 in Human Epidermal Keratinocytes: Implications for Preventing Arsenic-Induced Skin Cancer.

PubMed

Shah, Palak; Trinh, Elaine; Qiang, Lei; Xie, Lishi; Hu, Wen-Yang; Prins, Gail S; Pi, Jingbo; He, Yu-Ying

2017-01-24

Exposure to inorganic arsenic in contaminated drinking water poses an environmental public health threat for hundreds of millions of people in the US and around the world. Arsenic is a known carcinogen for skin cancer. However, the mechanism by which arsenic induces skin cancer remains poorly understood. Here, we have shown that arsenic induces p62 expression in an autophagy-independent manner in human HaCaT keratinocytes. In mouse skin, chronic arsenic exposure through drinking water increases p62 protein levels in the epidermis. Nrf2 is required for basal and arsenic-induced p62 up-regulation. p62 knockdown reduces arsenic-induced Nrf2 activity, and induces sustained p21 up-regulation. p62 induction is associated with increased proliferation in mouse epidermis. p62 knockdown had little effect on arsenic-induced apoptosis, while it decreased cell proliferation following arsenic treatment. Our findings indicate that arsenic induces p62 expression to regulate the Nrf2 pathway in human keratinocytes and suggest that targeting p62 may help prevent arsenic-induced skin cancer.

Epidermal differentiation in embryos of the tuatara Sphenodon punctatus (Reptilia, Sphenodontidae) in comparison with the epidermis of other reptiles.

PubMed

Alibardi, L; Gill, B J

2007-07-01

Studying the epidermis in primitive reptiles can provide clues regarding evolution of the epidermis during land adaptation in vertebrates. With this aim, the development of the skin of the relatively primitive reptile Sphenodon punctatus in representative embryonic stages was studied by light and electron microscopy and compared with that of other reptiles previously studied. The dermis organizes into a superficial and deep portion when the epidermis starts to form the first layers. At embryonic stages comparable with those of lizards, only one layer of the inner periderm is formed beneath the outer periderm. This also occurs in lizards and snakes so far studied. The outer and inner periderm form the embryonic epidermis and accumulate thick, coarse filaments (25-30 nm thick) and sparse alpha-keratin filaments as in other reptiles. Beneath the embryonic epidermis an oberhautchen and beta-cells form small horny tips that represent overlapping borders along the margin of beta-cells that overlap other beta-cells (in a tile-like arrangement). The tips resemble those of agamine lizards but at a small scale, forming a lamellate-spinulated pattern as previously described in adult epidermis. The embryonic epidermis matures by the dispersion of coarse filaments among keratin at the end of embryonic development and is shed around hatching. The presence of these matrix organelles in the embryonic epidermis of this primitive reptile further indicates that amniote epidermis acquired interkeratin matrix proteins early for land adaptation. Unlike the condition in lizards and snakes, a shedding complex is not formed in the epidermis of embryonic S. punctatus that is like that of the adult. Therefore, as in chelonians and crocodilians, the epidermis of S. punctatus also represents an initial stage that preceded the evolution of the shedding complex for moulting.

Epidermal differentiation in embryos of the tuatara Sphenodon punctatus (Reptilia, Sphenodontidae) in comparison with the epidermis of other reptiles

PubMed Central

Alibardi, L; Gill, B J

2007-01-01

Studying the epidermis in primitive reptiles can provide clues regarding evolution of the epidermis during land adaptation in vertebrates. With this aim, the development of the skin of the relatively primitive reptile Sphenodon punctatus in representative embryonic stages was studied by light and electron microscopy and compared with that of other reptiles previously studied. The dermis organizes into a superficial and deep portion when the epidermis starts to form the first layers. At embryonic stages comparable with those of lizards, only one layer of the inner periderm is formed beneath the outer periderm. This also occurs in lizards and snakes so far studied. The outer and inner periderm form the embryonic epidermis and accumulate thick, coarse filaments (25–30 nm thick) and sparse alpha-keratin filaments as in other reptiles. Beneath the embryonic epidermis an oberhautchen and beta-cells form small horny tips that represent overlapping borders along the margin of beta-cells that overlap other beta-cells (in a tile-like arrangement). The tips resemble those of agamine lizards but at a small scale, forming a lamellate-spinulated pattern as previously described in adult epidermis. The embryonic epidermis matures by the dispersion of coarse filaments among keratin at the end of embryonic development and is shed around hatching. The presence of these matrix organelles in the embryonic epidermis of this primitive reptile further indicates that amniote epidermis acquired interkeratin matrix proteins early for land adaptation. Unlike the condition in lizards and snakes, a shedding complex is not formed in the epidermis of embryonic S. punctatus that is like that of the adult. Therefore, as in chelonians and crocodilians, the epidermis of S. punctatus also represents an initial stage that preceded the evolution of the shedding complex for moulting. PMID:17532799

Quantitative comparison of the spreading and invasion of radial growth phase and metastatic melanoma cells in a three-dimensional human skin equivalent model.

PubMed

Haridas, Parvathi; McGovern, Jacqui A; McElwain, Sean D L; Simpson, Matthew J

2017-01-01

Standard two-dimensional (2D) cell migration assays do not provide information about vertical invasion processes, which are critical for melanoma progression. We provide information about three-dimensional (3D) melanoma cell migration, proliferation and invasion in a 3D melanoma skin equivalent (MSE) model. In particular, we pay careful attention to compare the structure of the tissues in the MSE with similarly-prepared 3D human skin equivalent (HSE) models. The HSE model is identically prepared to the MSE model except that melanoma cells are omitted. Using the MSE model, we examine melanoma migration, proliferation and invasion from two different human melanoma cell lines. One cell line, WM35, is associated with the early phase of the disease where spreading is thought to be confined to the epidermis. The other cell line, SK-MEL-28, is associated with the later phase of the disease where spreading into the dermis is expected. 3D MSE and HSE models are constructed using human de-epidermised dermis (DED) prepared from skin tissue. Primary fibroblasts and primary keratinocytes are used in the MSE and HSE models to ensure the formation of a stratified epidermis, with a well-defined basement membrane. Radial spreading of cells across the surface of the HSE and MSE models is observed. Vertical invasion of melanoma cells downward through the skin is observed and measured using immunohistochemistry. All measurements of invasion are made at day 0, 9, 15 and 20, providing detailed time course data. Both HSE and MSE models are similar to native skin in vivo , with a well-defined stratification of the epidermis that is separated from the dermis by a basement membrane. In the HSE and MSE we find fibroblast cells confined to the dermis, and differentiated keratinocytes in the epidermis. In the MSE, melanoma cells form colonies in the epidermis during the early part of the experiment. In the later stage of the experiment, the melanoma cells in the MSE invade deeper into the tissues. Interestingly, both the WM35 and SK-MEL-28 melanoma cells lead to a breakdown of the basement membrane and eventually enter the dermis. However, these two cell lines invade at different rates, with the SK-MEL-28 melanoma cells invading faster than the WM35 cells. The MSE and HSE models are a reliable platform for studying melanoma invasion in a 3D tissue that is similar to native human skin. Interestingly, we find that the WM35 cell line, that is thought to be associated with radial spreading only, is able to invade into the dermis. The vertical invasion of melanoma cells into the dermal region appears to be associated with a localised disruption of the basement membrane. Presenting our results in terms of time course data, along with images and quantitative measurements of the depth of invasion extends previous 3D work that has often been reported without these details.

Quantitative comparison of the spreading and invasion of radial growth phase and metastatic melanoma cells in a three-dimensional human skin equivalent model

PubMed Central

Haridas, Parvathi; McGovern, Jacqui A.; McElwain, Sean D.L.

2017-01-01

Background Standard two-dimensional (2D) cell migration assays do not provide information about vertical invasion processes, which are critical for melanoma progression. We provide information about three-dimensional (3D) melanoma cell migration, proliferation and invasion in a 3D melanoma skin equivalent (MSE) model. In particular, we pay careful attention to compare the structure of the tissues in the MSE with similarly-prepared 3D human skin equivalent (HSE) models. The HSE model is identically prepared to the MSE model except that melanoma cells are omitted. Using the MSE model, we examine melanoma migration, proliferation and invasion from two different human melanoma cell lines. One cell line, WM35, is associated with the early phase of the disease where spreading is thought to be confined to the epidermis. The other cell line, SK-MEL-28, is associated with the later phase of the disease where spreading into the dermis is expected. Methods 3D MSE and HSE models are constructed using human de-epidermised dermis (DED) prepared from skin tissue. Primary fibroblasts and primary keratinocytes are used in the MSE and HSE models to ensure the formation of a stratified epidermis, with a well-defined basement membrane. Radial spreading of cells across the surface of the HSE and MSE models is observed. Vertical invasion of melanoma cells downward through the skin is observed and measured using immunohistochemistry. All measurements of invasion are made at day 0, 9, 15 and 20, providing detailed time course data. Results Both HSE and MSE models are similar to native skin in vivo, with a well-defined stratification of the epidermis that is separated from the dermis by a basement membrane. In the HSE and MSE we find fibroblast cells confined to the dermis, and differentiated keratinocytes in the epidermis. In the MSE, melanoma cells form colonies in the epidermis during the early part of the experiment. In the later stage of the experiment, the melanoma cells in the MSE invade deeper into the tissues. Interestingly, both the WM35 and SK-MEL-28 melanoma cells lead to a breakdown of the basement membrane and eventually enter the dermis. However, these two cell lines invade at different rates, with the SK-MEL-28 melanoma cells invading faster than the WM35 cells. Discussion The MSE and HSE models are a reliable platform for studying melanoma invasion in a 3D tissue that is similar to native human skin. Interestingly, we find that the WM35 cell line, that is thought to be associated with radial spreading only, is able to invade into the dermis. The vertical invasion of melanoma cells into the dermal region appears to be associated with a localised disruption of the basement membrane. Presenting our results in terms of time course data, along with images and quantitative measurements of the depth of invasion extends previous 3D work that has often been reported without these details. PMID:28890854

Alternatives to In Vivo Draize Rabbit Eye and Skin Irritation Tests with a Focus on 3D Reconstructed Human Cornea-Like Epithelium and Epidermis Models

PubMed Central

Lee, Miri; Hwang, Jee-Hyun; Lim, Kyung-Min

2017-01-01

Human eyes and skin are frequently exposed to chemicals accidentally or on purpose due to their external location. Therefore, chemicals are required to undergo the evaluation of the ocular and dermal irritancy for their safe handling and use before release into the market. Draize rabbit eye and skin irritation test developed in 1944, has been a gold standard test which was enlisted as OECD TG 404 and OECD TG 405 but it has been criticized with respect to animal welfare due to invasive and cruel procedure. To replace it, diverse alternatives have been developed: (i) For Draize eye irritation test, organotypic assay, in vitro cytotoxicity-based method, in chemico tests, in silico prediction model, and 3D reconstructed human cornea-like epithelium (RhCE); (ii) For Draize skin irritation test, in vitro cytotoxicity-based cell model, and 3D reconstructed human epidermis models (RhE). Of these, RhCE and RhE models are getting spotlight as a promising alternative with a wide applicability domain covering cosmetics and personal care products. In this review, we overviewed the current alternatives to Draize test with a focus on 3D human epithelium models to provide an insight into advancing and widening their utility. PMID:28744350

Functional melanocytes derived from human pluripotent stem cells engraft into pluristratified epidermis.

PubMed

Nissan, Xavier; Larribere, Lionel; Saidani, Manoubia; Hurbain, Ilse; Delevoye, Cédric; Feteira, Jessica; Lemaitre, Gilles; Peschanski, Marc; Baldeschi, Christine

2011-09-06

Melanocytes are essential for skin homeostasis and protection, and their defects in humans lead to a wide array of diseases that are potentially extremely severe. To date, the analysis of molecular mechanisms and the function of human melanocytes have been limited because of the difficulties in accessing large numbers of cells with the specific phenotypes. This issue can now be addressed via a differentiation protocol that allows melanocytes to be obtained from pluripotent stem cell lines, either induced or of embryonic origin, based on the use of moderate concentrations of a single cytokine, bone morphogenic protein 4. Human melanocytes derived from pluripotent stem cells exhibit all the characteristic features of their adult counterparts. This includes the enzymatic machinery required for the production and functional delivery of melanin to keratinocytes. Melanocytes also integrate appropriately into organotypic epidermis reconstructed in vitro. The availability of human cells committed to the melanocytic lineage in vitro will enable the investigation of those mechanisms that guide the developmental processes and will facilitate analysis of the molecular mechanisms responsible for genetic diseases. Access to an unlimited resource may also prove a vital tool for the treatment of hypopigmentation disorders when donors with matching haplotypes become available in clinically relevant banks of pluripotent stem cell lines.

Differentiation of the epidermis in turtle: an immunocytochemical, autoradiographic and electrophoretic analysis.

PubMed

Alibardi, Lorenzo; Spisni, Enzo; Toni, Mattia

2004-01-01

Proteins involved in the process of cornification of turtle epidermis are not well known. The present immunocytochemical, electrophoretic and autoradiographic study reports on the localization patterns and molecular weights of keratins, which are cornification proteins, and of tritiated histidine in turtle epidermis. Alpha-keratins with a molecular weight of 40-62 kDa are present in the epidermis. Beta-keratin is mainly detectable in the stratum corneum of the carapace and plastron, but is rarely present or even absent in the corneous layer of limb, tail and neck epidermis. After electrophoresis and immunoblotting with an antibody against chicken scale beta-keratin, bands at 15-17, 22-24, and 36-38 kDa appeared. This antibody recognized weaker bands at 38-40 and 58-60 kDa in the soft epidermis. After reduction and carboxymethylation of proteins extracted from carapace and plastron, but not of proteins from the soft epidermis, protein bands at 15-17 and 35-37 kDa were found when using the anti-beta 1-keratin antibody. Loricrin-, filaggrin-, sciellin-, and transglutaminase-like immunostaining was detectable only in the transitional and lowermost corneous layers of the soft epidermis. Vesicular bodies in the transitional layer were immunolabeled by the anti-loricrin antibody, and weakly by the anti-filaggrin and anti-transglutaminase antibodies. In immunoblots, the anti-loricrin antibody reacted with a major band at 50-54 kDa in both carapace-plastron and soft epidermis. The anti-sciellin antibody detected major bands at 38-40 and 50 kDa in hard epidermis, and at 50 and 54-56 kDa in soft epidermis. Filaggrin-like immunostained bands were observed at 50-55 and 62-64 kDa. This immunostaining was probably due to a common epitope in filaggrin and some keratins. Histidine was evenly incorporated in the epidermis, and the ultrastructural study showed random labeling, often associated with keratin bundles of alpha and beta-keratinocytes. Histidine-labeled protein bands were not found in the carapace-plastron. In the soft epidermis, weakly labeled bands at 15-20, 25, and 45-60 kDa were found occasionally. The latter bands probably represented neo-synthesized keratins as was also indicated by the ultrastructural autoradiographic analysis. In conclusion, our study suggests that proteins with epitopes that they have in common with cornification proteins of mammalian epidermis are also present in the epidermis of turtle.

3D printing-assisted fabrication of double-layered optical tissue phantoms for laser tattoo treatments.

PubMed

Kim, Hanna; Hau, Nguyen Trung; Chae, Yu-Gyeong; Lee, Byeong-Il; Kang, Hyun Wook

2016-04-01

Artificial skin phantoms have been developed as an alternative tissue for human skin experiments due to convenient use and easy storage. However, fabricating both thin (∼100 μm) epidermis and relatively thick dermis is often cumbersome, and most developed phantoms have hardly reflected specific human skin types. The objective of this study was to fabricate skin phantoms with 3D printing technique to emulate various human skin types (I-VI) along with the corresponding optical and mechanical properties for laser tattoo removal. Both gelatin and agar powders were mixed with coffee and TiO2 particles to fabricate skin phantoms with materials properties for various skin types (I-VI). A 3D printer was employed to precisely control the thickness of each phantom for epidermis and dermis layers. A number of concentrations of the coffee and TiO2 particles were used to determine the degree of absorption and scattering effects in various skin types. The optical properties between 500 and 1,000 nm for the fabricated phantoms were measured by double-integrating spheres with an inverse adding-doubling (IAD) algorithm. Optical coherence tomography (OCT) and rheometer were also utilized to evaluate optical (absorption and reduced scattering coefficients) and mechanical properties (compression modulus) of the fabricated phantoms, respectively. Visible color inspections presented that the skin phantoms for types I, III, and VI similarly emulated the color space of the human skin types. The optical property measurements demonstrated that the absorption (μa) and reduced scattering (μ(s')) coefficients decreased with wavelengths. Compared to the human skin type VI, a dermis phantom represented quite equivalent values of μa and μ(s') whereas an epidermis phantom showed up to 30% lower μa but almost identical μ(s') over the wavelengths. The OCT measurements confirmed that the thicknesses of the epidermis and the dermis phantoms were measured to be 138.50 ± 0.01 μm and 0.81 ± 0.04 mm, respectively. The mechanical properties of the phantoms mixed with the agar volume of 40% yielded a compression modulus of 83.7 ± 14.8 kPa, which well corresponded to that of human forearm skin (50-95 kPa). The 3D printing technique was able to reliably fabricate the double-layered phantoms emulating a variety of skin types (I-VI) along with the comparable optical and mechanical properties. Further investigations will incorporate artificial chromophores into the fabricated skin phantoms to reliably evaluate the new therapeutic wavelengths for laser tattoo removal. © 2016 Wiley Periodicals, Inc.

Topical delivery of a preformed photosensitizer for photodynamic therapy of cutaneous lesions

NASA Astrophysics Data System (ADS)

Oleinick, Nancy L.; Kenney, Malcolm E.; Lam, Minh; McCormick, Thomas; Cooper, Kevin D.; Baron, Elma D.

2012-02-01

Photosensitizers for photodynamic therapy (PDT) are most commonly delivered to patients or experimental animals via intravenous injection. After initial distribution throughout the body, there can be some preferential accumulation within tumors or other abnormal tissue in comparison to the surrounding normal tissue. In contrast, the photosensitizer precursor, 5-aminolevulinic acid (ALA) or one of its esters, is routinely administered topically, and more specifically, to target skin lesions. Following metabolic conversion to protoporphyrin IX, the target area is photoilluminated, limiting peripheral damage and targeting the effective agent to the desired region. However, not all skin lesions are responsive to ALA-PDT. Topical administration of fully formed photosensitizers is less common but is receiving increased attention, and some notable advances with selected approved and experimental photosensitizers have been published. Our team has examined topical administration of the phthalocyanine photosensitizer Pc 4 to mammalian (human, mouse, pig) skin. Pc 4 in a desired formulation and concentration was applied to the skin surface at a rate of 5-10 μL/cm2 and kept under occlusion. After various times, skin biopsies were examined by confocal microscopy, and fluorescence within regions of interest was quantified. Early after application, images show the majority of the Pc 4 fluorescence within the stratum corneum and upper epidermis. As a function of time and concentration, penetration of Pc 4 across the stratum corneum and into the epidermis and dermis was observed. The data indicate that Pc 4 can be delivered to skin for photodynamic activation and treatment of skin pathologies.

Xenobiotic metabolism capacities of human skin in comparison with a 3D epidermis model and keratinocyte-based cell culture as in vitro alternatives for chemical testing: activating enzymes (Phase I).

PubMed

Götz, Christine; Pfeiffer, Roland; Tigges, Julia; Blatz, Veronika; Jäckh, Christine; Freytag, Eva-Maria; Fabian, Eric; Landsiedel, Robert; Merk, Hans F; Krutmann, Jean; Edwards, Robert J; Pease, Camilla; Goebel, Carsten; Hewitt, Nicola; Fritsche, Ellen

2012-05-01

Skin is important for the absorption and metabolism of exposed chemicals such as cosmetics or pharmaceuticals. The Seventh Amendment to the EU Cosmetics Directive prohibits the use of animals for cosmetic testing for certain endpoints, such as genotoxicity; therefore, there is an urgent need to understand the xenobiotic metabolizing capacities of human skin and to compare these activities with reconstructed 3D skin models developed to replace animal testing. We have measured Phase I enzyme activities of cytochrome P450 (CYP) and cyclooxygenase (COX) in ex vivo human skin, the 3D skin model EpiDerm™ (EPI-200), immortalized keratinocyte-based cell lines and primary normal human epidermal keratinocytes. Our data demonstrate that basal CYP enzyme activities are very low in whole human skin and EPI-200 as well as keratinocytes. In addition, activities in monolayer cells differed from organotypic tissues after induction. COX activity was similar in skin, EPI-200 and NHEK cells, but was significantly lower in immortalized keratinocytes. Hence, the 3D model EPI-200 might represent a more suitable model for dermatotoxicological studies. Altogether, these data help to better understand skin metabolism and expand the knowledge of in vitro alternatives used for dermatotoxicity testing. © 2012 John Wiley & Sons A/S.

Diagnostics of cancer tissues by fiber optic evanescent wave Fourier transform IR (FEW-FTIR) spectroscopy

NASA Astrophysics Data System (ADS)

Afanasyeva, Natalia I.; Kolyakov, Sergei F.; Letokhov, Vladilen S.; Golovkina, Viktoriya N.

1997-08-01

Fiber optic evanescent wave Fourier transform infrared (FEW- FTIR) spectroscopy using fiberoptic sensors operated in the attenuated total reflection (ATR) regime in the middle infrared (IR) region of the spectrum (850 - 1850 cm-1) has recently found application in the diagnostics of tissues. The method is suitable for noninvasive and rapid (seconds) direct measurements of the spectra of normal and pathological tissues in vitro, ex vivo and in vivo. The aim of our studies is the express testing of various tumor tissues at the early stages of their development. The method is expected to be further developed for endoscopic and biopsy applications. We measured in vivo the skin normal and malignant tissues on surface (directly on patients) in various cases of basaloma, melanoma and nevus. The experiments were performed in operating room for measurements of skin in the depth (under/in the layers of epidermis), human breast, stomach, lung, kidney tissues. The breast and skin tissues at different stages of tumor or cancer were distinguished very clearly in spectra of amide, side cyclic and noncyclic hydrogen bonded fragments of aminoacid residuals, phosphate groups and sugars. Computer monitoring is being developed for diagnostics.

Molecular IR Spectroscopy: New Trends and Methods of Noninvasive Diagnostics of Tissue IN VIVO

NASA Astrophysics Data System (ADS)

Afanasyeva, Natalia; Bruch, Reinhard

1998-05-01

Fiberoptic evanescent wave Fourier transform infrared (FEW-FTIR) spectroscopy using fiberoptic sensors operated in the attenuated total reflection (ATR) regime in the middle infrared (IR) region of the spectrum (850-1850 cm-1) has recently been applied to the diagnostics of tissues. The method is suitable for noninvasive and rapid (seconds) direct measurements of the spectra of normal and pathological tissues in vitro, ex vivo and in vivo. The aim of our studies is the express testing of various tumor tissues at the early stages of their development. The method is expected to be further developed for endoscopic and biopsy applications. We measured the normal skin and malignant tissues in vivo on the surface (directly on patients) in various cases of basaloma, melanoma and nevus. The experiments were performed in the operating room to measure the skin in the depth (under/in the layers of epidermis) of human breast, stomach, lung, and kidney tissues. The breast and skin tissues at different stages of tumor or cancer were distinguished very clearly in spectra of amide, side cyclic and noncyclic hydrogen bonded fragments of aminoacid residuals, phosphate groups and sugars. Computer monitoring is being developed for diagnostics.

Electric Potential Across Epidermis and Its Role During Wound Healing Can Be Studied by Using an In Vitro Reconstructed Human Skin

PubMed Central

Moulin, Véronique J.; Dubé, Jean; Rochette-Drouin, Olivier; Lévesque, Philippe; Gauvin, Robert; Roberge, Charles J.; Auger, François A.; Goulet, Daniel; Bourdages, Michel; Plante, Michel; Germain, Lucie

2012-01-01

Background After human epidermis wounding, transepithelial potential (TEP) present in nonlesional epidermis decreases and induces an endogenous direct current epithelial electric field (EEF) that could be implicated in the wound re-epithelialization. Some studies suggest that exogenous electric stimulation of wounds can stimulate healing, although the mechanisms remain to be determined. The Problem Little is known concerning the exact action of the EEF during healing. The mechanism responsible for TEP and EEF is unknown due to the lack of an in vitro model to study this phenomenon. Basic Science Advances We carried out studies by using a wound created in a human tissue-engineered skin and determined that TEP undergoes ascending and decreasing phases during the epithelium formation. The in vitro TEP measurements over time in the wound were corroborated with histological changes and with in vivo TEP variations during porcine skin wound healing. The expression of a crucial element implicated in Na+ transport, Na+/K+ ATPase pumps, was also evaluated at the same time points during the re-epithelialization process. The ascending and decreasing TEP values were correlated with changes in the expression of these pumps. The distribution of Na+/K+ ATPase pumps also varied according to epidermal differentiation. Further, inhibition of the pump activity induced a significant decrease of the TEP and of the re-epithelization rate. Clinical Care Relevance A better comprehension of the role of EEF could have important future medical applications regarding the treatment of chronic wound healing. Conclusion This study brings a new perspective to understand the formation and restoration of TEP during the cutaneous wound healing process. PMID:24527285

Melanin fate in the human epidermis: a reassessment of how best to detect and analyse histologically.

PubMed

Joly-Tonetti, Nicolas; Wibawa, Judata I D; Bell, Mike; Tobin, Desmond

2016-07-01

Melanin is the predominant pigment responsible for skin colour and is synthesized by the melanocyte in the basal layer of the epidermis and then transferred to surrounding keratinocytes. Despite its optical properties, melanin is barely detectable in unstained sections of human epidermis. However, identification and localization of melanin is of importance for the study of skin pigmentation in health and disease. Current methods for the histologic quantification of melanin are suboptimal and are associated with significant risk of misinterpretation. The aim of this study was to reassess the existing literature and to develop a more effective histological method of melanin quantification in human skin. Moreover, we confirm that Warthin-Starry (WS) stain provides a much more sensitive and more specific melanin detection method than the commonplace Fontana-Masson (FM) stain. For example, WS staining sensitivity allowed the visualization of melanin even in very pale Caucasian skin that was missed by FM or Von Kossa (VK) stains. From our reassessment of the histology-related literature, we conclude that so-called melanin dust is most likely an artifact of discoloration due to non-specific silver deposition in the stratum corneum. Unlike FM and VK, WS was not associated with this non-specific stratum corneum darkening, misinterpreted previously as 'degraded' melanin. Finally, WS melanin particle counts were largely similar to previously reported manual counts by transmission electron microscopy, in contrast to both FM and VK. Together these findings allow us to propose a new histology/Image J-informed method for the accurate and precise quantification of epidermal melanin in skin. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

THE SUSCEPTIBILITY OF CHICK EMBRYO SKIN ORGAN CULTURES TO INFLUENZA VIRUS FOLLOWING EXCESS VITAMIN A

PubMed Central

Huang, J. S.; Bang, F. B.

1964-01-01

The conversion of chick embryonic epidermis to mucous epithelium by excess vitamin A in organ culture as reported by Fell and Mellanby (5) was shown to be accompanied by a corresponding change of susceptibility to influenza and vaccinia viruses. Untreated epidermis of 10- to 12-day chick embryos supported the growth of influenza (PR8) virus in organ cultures and a maximum infectivity (EID50) titer was reached 2 to 3 days after infection. At the same time) the epidermis showed squamous keratinization, beginning about the 4th day of cultivation. Addition of excess vitamin A (40 µg per ml) to the skin organ culture induced the following changes: (a) mucous metaplasia of the epidermis which was usually first evident after 4 to 5 days in the vitamin A medium, (b) increase in the daily and maximum yield of influenza virus, if the epidermis had been grown for 4 or more days in the vitamin A medium before infection took place, and (c) decrease in the production of vaccinia virus under similar conditions. The maximum yield of both viruses remained unchanged, however, if excess vitamin A was introduced to the organ culture at the time of virus inoculation. The magnitude of increase in the yield of influenza virus in this organ culture system was found to be proportionally related to the concentration of vitamin A added 4 or more days before inoculation of this virus. Increasing doses of vitamin A however, had no effect on the short-term growth of influenza virus in tissue cultures of chorio-allantoic membrane. Observation on the early period (2 to 12 hours) of influenza virus growth initiated in the 4-day organ cultures of chick embryonic skin showed no significant difference in virus production between the normal and the vitamin A medium groups. The change of virus specificity apparently is not due to the presence of excess vitamin A per se, but appears to be related to the change of differentiation produced in the organ culture system. PMID:14206436

Studies on the cellular and subcellular reactions in epidermis at irritant and allergic dermatitis.

PubMed

Lindberg, M

1982-01-01

To determine the cellular and subcellular reactions of keratinocytes at contact dermatitis, transmission electron microscopy was used in combination with energy dispersive X-ray microanalysis. Stereology and optical diffraction were used as complements to electron microscopy for studies of the effects of variations in the preparation technique on the ultrastructure of epidermis. The morphological effects of an increased hydration of epidermis were assessed by the use of occlusive patch tests. It was found that the relative volume of the epidermal intercellular space and the ultrastructure of the epidermal cells (keratinocytes and Langerhans' cells) were directly dependent on the osmolality of the fixative vehicle if glutaraldehyde was used as fixative. Cellular volume and morphology did also depend on the fixative used. Variations in the volume of the intercellular space were also detected when the water transport through epidermis was impaired by occlusive treatment. In normal epidermis prolonged fixation times (4 weeks) did not affect the morphology of the keratinocytes. However, if the structure and function of the keratinocytes were affected by the application of a irritant substance (DNCB), a loss of electron dense material from the cells was detected within 3 weeks. The ultrastructural changes in the keratinocytes at the irritant chromate and DNCB reactions were of a non-specific nature and are in accordance with the changes described for other irritant agents in the literature. A few cells with the features of apoptosis were recorded. The allergic chromate reaction was found to be a combination of the irritant reaction and a marked inflammatory response. To correlate the ultrastructural alterations in the keratinocytes with the functional state of the cells, X-ray microanalysis was used to determine the elemental redistribution occurring at the irritant DNCB reaction. The results of the X-ray microanalysis showed a good correlation between dose and time dependent effects and with the ultrastructural changes. Cell injury in the keratinocytes lead to decreases in the cellular content of phosphorous, potassium and magnesium and an increase of cellular calcium. Sodium, chloride, and sulphur were only moderately changed. A stimulation of the basal keratinocytes was detectable when a weak DNCB dose was applied to the skin.

Neuropilin 1 Receptor Is Up-Regulated in Dysplastic Epithelium and Oral Squamous Cell Carcinoma.

PubMed

Shahrabi-Farahani, Shokoufeh; Gallottini, Marina; Martins, Fabiana; Li, Erik; Mudge, Dayna R; Nakayama, Hironao; Hida, Kyoko; Panigrahy, Dipak; D'Amore, Patricia A; Bielenberg, Diane R

2016-04-01

Neuropilins are receptors for disparate ligands, including proangiogenic factors such as vascular endothelial growth factor and inhibitory class 3 semaphorin (SEMA3) family members. Differentiated cells in skin epithelium and cutaneous squamous cell carcinoma highly express the neuropilin-1 (NRP1) receptor. We examined the expression of NRP1 in human and mouse oral mucosa. NRP1 was significantly up-regulated in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC). NRP1 receptor localized to the outer suprabasal epithelial layers in normal tongue, an expression pattern similar to the normal skin epidermis. However, dysplastic tongue epithelium and OSCC up-regulated NRP1 in basal and proliferating epithelial layers, a profile unseen in cutaneous squamous cell carcinoma. NRP1 up-regulation is observed in a mouse carcinogen-induced OSCC model and in human tongue OSCC biopsies. Human OSCC cell lines express NRP1 protein in vitro and in mouse tongue xenografts. Sites of capillary infiltration into orthotopic OSCC tumors correlate with high NRP1 expression. HSC3 xenografts, which express the highest NRP1 levels of the cell lines examined, showed massive intratumoral lymphangiogenesis. SEMA3A inhibited OSCC cell migration, suggesting that the NRP1 receptor was bioactive in OSCC. In conclusion, NRP1 is regulated in the oral epithelium and is selectively up-regulated during epithelial dysplasia. NRP1 may function as a reservoir to sequester proangiogenic ligands within the neoplastic compartment, thereby recruiting neovessels toward tumor cells. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Analysis of the Molecular Mechanisms of Reepithelialization in Drosophila Embryos

PubMed Central

Matsubayashi, Yutaka; Millard, Tom H.

2016-01-01

Significance: The epidermis provides the main barrier function of skin, and therefore its repair following wounding is an essential component of wound healing. Repair of the epidermis, also known as reepithelialization, occurs by collective migration of epithelial cells from around the wound edge across the wound until the advancing edges meet and fuse. Therapeutic manipulation of this process could potentially be used to accelerate wound healing. Recent Advances: It is difficult to analyze the cellular and molecular mechanisms of reepithelialization in human tissue, so a variety of model organisms have been used to improve our understanding of the process. One model system that has been especially useful is the embryo of the fruit fly Drosophila, which provides a simple, accessible model of the epidermis and can be manipulated genetically, allowing detailed analysis of reepithelialization at the molecular level. This review will highlight the key insights that have been gained from studying reepithelialization in Drosophila embryos. Critical Issues: Slow reepithelialization increases the risk of wounds becoming infected and ulcerous; therefore, the development of therapies to accelerate or enhance the process would be a great clinical advance. Improving our understanding of the molecular mechanisms that underlie reepithelialization will help in the development of such therapies. Future Directions: Research in Drosophila embryos has identified a variety of genes and proteins involved in triggering and driving reepithelialization, many of which are conserved in humans. These novel reepithelialization proteins are potential therapeutic targets and therefore findings obtained in Drosophila may ultimately lead to significant clinical advances. PMID:27274434

A Multiscale Computational Model of the Response of Swine Epidermis After Acute Irradiation

NASA Technical Reports Server (NTRS)

Hu, Shaowen; Cucinotta, Francis A.

2012-01-01

Radiation exposure from Solar Particle Events can lead to very high skin dose for astronauts on exploration missions outside the protection of the Earth s magnetic field [1]. Assessing the detrimental effects to human skin under such adverse conditions could be predicted by conducting territorial experiments on animal models. In this study we apply a computational approach to simulate the experimental data of the radiation response of swine epidermis, which is closely similar to human epidermis [2]. Incorporating experimentally measured histological and cell kinetic parameters into a multiscale tissue modeling framework, we obtain results of population kinetics and proliferation index comparable to unirradiated and acutely irradiated swine experiments [3]. It is noted the basal cell doubling time is 10 to 16 days in the intact population, but drops to 13.6 hr in the regenerating populations surviving irradiation. This complex 30-fold variation is proposed to be attributed to the shortening of the G1 phase duration. We investigate this radiation induced effect by considering at the sub-cellular level the expression and signaling of TGF-beta, as it is recognized as a key regulatory factor of tissue formation and wound healing [4]. This integrated model will allow us to test the validity of various basic biological rules at the cellular level and sub-cellular mechanisms by qualitatively comparing simulation results with published research, and should lead to a fuller understanding of the pathophysiological effects of ionizing radiation on the skin.

Blood-feeding of Tunga penetrans males.

PubMed

Witt, L H; Linardi, P M; Meckes, O; Schwalfenberg, S; Ribeiro, R A; Feldmeier, H; Heukelbach, J

2004-12-01

The jigger Tunga penetrans (Linnaeus, 1758: type-species of the family Tungidae) is the smallest known species of flea (Siphonaptera), causing serious ectoparasitosis of humans and domestic animals. The adult female Tunga lodges in the epidermis of the mammalian host, grows by neosomy, becomes gravid and expels eggs. Relatively little is known about the free-living male Tunga adults. Among impoverished communities of Fortaleza in north-east Brazil, we observed T. penetrans males as well as females penetrating the skin of human hosts. After penetrating the epidermis for a few hours, evidently for capillary feeding from the dermis, males withdrew their mouthparts and crawled away, whereas the females remained completely embedded, hypertrophying to become gravid, eventually dying in situ after oviposition. Caged rats were placed on the sandy soil and examined periodically for Tunga infestation. On five rats we obtained 140 females embedded and we detected 75 males biting, with rat erythrocytes observed in the proventriculus and midgut of all five males dissected and examined microscopically. This confirms that T. penetrans males are hamatophagous ectoparasites of mammals.

In-vivo optical investigation of psoriasis

NASA Astrophysics Data System (ADS)

Kapsokalyvas, Dimitrios; Cicchi, Riccardo; Bruscino, Nicola; Alfieri, Domenico; Massi, Daniela; Lotti, Torello; Pavone, Francesco S.

2011-03-01

Psoriasis is an autoimmune disease of the skin characterized by hyperkeratosis, hyperproliferation of the epidermis, inflammatory cell accumulation and increased dilatation of dermal papillary blood vessels. Cases of psoriasis were investigated in vivo with optical means in order to evaluate the potential of in vivo optical biopsy. A Polarization Multispectral Dermoscope was employed for the macroscopic observation. Features such as the 'dotted' blood vessels pattern was observed with high contrast. The average size of dot vessels in Psoriasis was measured to be 974 μm2 which is much higher compared to healthy skin. High resolution image sections of the epidermis and the dermis were produced with a custom made Multiphoton Microscope. Imaging extended from the surface of the lesion down to the papillary dermis, at a depth of 200 μm. In the epidermis, a characteristic morphology of the stratum corneum found only in Psoriasis was revealed. Additionally, the cytoplasmic area of the cells in the stratum spinosum layer was found to be smaller than normal. In the dermis the morphological features were more pronounced, where the elongated dermal papillae dominated the papillary layer. Their length exceeds 100μm, which is a far greater value compared to that of healthy skin. These in vivo observations are consistent with the ex vivo histopathological observations, supporting both the applicability and potentiality of multispectral dermoscopy and multiphoton microscopy in the field of in vivo optical investigation and biopsy of skin.

Hair-cycle dependent differential expression of ADAM 10 and ADAM 12

PubMed Central

Cho, Baik-Kee; Schramme, Anja; Gutwein, Paul; Tilgen, Wolfgang; Reichrath, Jörg

2009-01-01

Background ADAM proteases play important roles in processes of development and differentiation. However, no report has been found in the literature addressing the expression and function of ADAM proteases during hair cycling. Results Cytoplasmic expression pattern of ADAM 10, 12 was similar between normal epidermis and hair infundibulum. In addition, cytoplasmic expression of ADAM 10 was observed in the hair bulb keratinocytes and fibroblasts of dermal papilla in anagen I–III hair follicles. In contrast, decreased ADAM 10 expression was observed in the hair matrix keratinocytes as compared to the hair bulb keratinocytes in anagen I–III hair follicles. Interestingly, ADAM 10 immunoreactivity was expressed weakly in the lower portion of outer root sheath (ORS) of anagen VI hair follicles, and strong ADAM 10 expression was detected in the ORS of catagen and telogen hair follicles. By contrast, ADAM 12 expression was not detected in the hair bulb keratinocytes of anagen I–III hair follicles. ADAM 12 immunoreactivity firstly appeared in the inner root sheath ( IRS ) of anagen IV—V hair follicles and was down-regulated in the IRS and hair cortex and medulla of catagen hair follicles, Strong ADAM 12 immunoreactivity was observed in the ORS of catagen and telogen hair follicles. Material and methods Samples of normal human skin (n = 30) were used. Immunohistochemical analysis was performed using ADAM 10, 12 specific polyclonal antibodies and a sensitive streptavidin-peroxidase technique. Conclusion Our study demonstrates a comparable staining pattern of decreased ADAM 10 immunoreactivity in hair matrix keratinocytes and the basal cell layer of normal epidermis and hair infundibulum. Expression of ADAM 10 in dermal papilla cells may imply a role in the induction and development of anagen hair follicles. In addition, expression of ADAM 10 in the ORS and hair bulb assume the involvment of ADAM 10 in the downward migration of anagen hair follicles. Furthermore ADAM 12 expression in the IRS may indicate a role in the differentiation of anagen hair follicles. Downregulation of ADAM 12 upon the onset of catagen hair stage suggests that ADAM 12 may play an important role of ADAM 12 in the apoptosis of hair follicle keratinocytes. In summary our findings suggest that ADAM 10 and 12 may be of importance for the regulation of hair cycling. PMID:20046589

Correlation of trace element concentrations between epidermis and internal organ tissues in Indo-Pacific humpback dolphins (Sousa chinensis).

PubMed

Sun, Xian; Yu, Ri-Qing; Zhang, Mei; Zhang, Xiyang; Chen, Xi; Xiao, Yousheng; Ding, Yulong; Wu, Yuping

2017-12-15

Trace element accumulation in the epidermis of cetaceans has been less studied. This study explored the feasibility of using epidermis as a surrogate tissue to evaluate internal contaminant burdens in Indo-Pacific humpback dolphin (Sousa chinensis). Eleven trace elements were analyzed in the epidermis, muscle and liver tissues from 46 individuals of dolphins stranded along the Pearl River Estuary (PRE) coast between 2007 and 2013. Trace elemental concentrations varied among the three tissues, generally with the highest concentrations found in liver tissues and lowest in the epidermis (except Zn, As, and Pb). Zn concentration in the epidermis was the highest among all tissues, indicating that Zn could be an important element for the epidermis physiology. High concentrations of Hg and Cr in liver were likely due to an excessive intake by dolphins which consumed high Hg and Cr contaminated fishes in the PRE. Hg concentrations in epidermis and muscle tissues were significantly higher in the females than in males. Concentrations of V and Pb in liver, Se and Cd in both muscle and liver, and As and Hg in all tissue samples showed significantly positive relationships with body length. Hepatic Cu concentrations were significantly negatively correlated with the body length. Hg and As concentrations in epidermis showed significantly positive correlations with those in liver tissues. Thus this study proposed that epidermis could be used as a non-invasive monitoring tissue to evaluate Hg and As bioaccumulation in internal tissues of Indo-Pacific humpback dolphins populations. Copyright © 2017 Elsevier B.V. All rights reserved.

Topical stabilized retinol treatment induces the expression of HAS genes and HA production in human skin in vitro and in vivo.

PubMed

Li, Wen-Hwa; Wong, Heng-Kuan; Serrano, José; Randhawa, Manpreet; Kaur, Simarna; Southall, Michael D; Parsa, Ramine

2017-05-01

Skin Aging manifests primarily with wrinkles, dyspigmentations, texture changes, and loss of elasticity. During the skin aging process, there is a loss of moisture and elasticity in skin resulting in loss of firmness finally leading to skin sagging. The key molecule involved in skin moisture is hyaluronic acid (HA), which has a significant water-binding capacity. HA levels in skin decline with age resulting in decrease in skin moisture, which may contribute to loss of firmness. Clinical trials have shown that topically applied ROL effectively reduces wrinkles and helps retain youthful appearance. In the current study, ROL was shown to induce HA production and stimulates the gene expression of all three forms of hyaluronic acid synthases (HAS) in normal human epidermal keratinocytes monolayer cultures. Moreover, in human skin equivalent tissues and in human skin explants, topical treatment of tissues with a stabilized-ROL formulation significantly induced the gene expression of HAS mRNA concomitant with an increased HA production. Finally, in a vehicle-controlled human clinical study, histochemical analysis confirmed increased HA accumulation in the epidermis in ROL-treated human skin as compared to vehicle. These results show that ROL increases skin expression of HA, a significant contributing factor responsible for wrinkle formation and skin moisture, which decrease during aging. Taken together with the activity to increase collagen, elastin, and cell proliferation, these studies establish that retinol provides multi-functional activity for photodamaged skin.

In vitro co-culture of human skin keratinocytes and fibroblasts on a biocompatible and biodegradable scaffold.

PubMed

Pajoum Shariati, Seyed Ramin; Shokrgozar, Mohammad Ali; Vossoughi, Manouchehr; Eslamifar, Ali

2009-07-01

Extensive full-thickness burns require replacement of both epidermis and dermis. In designing skin replacements, the goal has been to re-create this model and make a product which has both essential components. In the present study, we developed procedures for establishing confluent, stratified layers of cultured human keratinocytes on the surface of modified collagen-chitosan scaffold that contains fibroblasts. The culture methods for propagation of keratinocytes and fibroblasts isolated from human neonatal foreskin were developed. The growth and proliferation of normal human keratinocytes were evaluated in serum-free (keratinocyte growth medium) and our modified medium. Characterization of human keratinocytes was determined by using pan-keratin and anti-involucrin monoclonal antibodies. For fabrication of relevant biodegradable and biocompatible collagen-chitosan porous scaffold with improved biostability, modified method of freeze-gelation was used. In generating organotypic co-cultures, epidermal keratinocytes were plated onto the upper surface of scaffold containing embedded fibroblasts. The results showed that the growth of isolated human skin fibroblasts and keratinocytes in our modified medium was more than that in the serum-free medium. The different evaluations of collagen-chitosan scaffold showed that it is relevant to growth of cells (fibroblast and keratinocyte) and has a good flexibility in manipulation of the living skin equivalents. These findings indicate that the integration of collagen-chitosan scaffold with co-cultured keratinocyte and fibroblast in vitro provides a potential source of living skin for grafting in vivo.

Contribution of glue layer into epidermis sample fluorescence dynamics

NASA Astrophysics Data System (ADS)

Salomatina, Elena V.; Chernova, Svetlana P.; Pravdin, Alexander B.

2000-04-01

In this work, the temporal behavior of autofluorescence of epidermis samples under UV-irradiation has ben studied. The samples were prepared using surface epidermis stripping technique. Fluorescence spectra and kinetic curves of fluorescence intensity have been obtained. It has been concluded that the glue composition used allows the measurement of epidermis fluorescence dynamics with the first 60 min of experiment.

The outer epidermis of Avena and maize coleoptiles is not a unique target for auxin in elongation growth

NASA Technical Reports Server (NTRS)

Cleland, R. E.

1991-01-01

A controversy exists as to whether or not the outer epidermis in coleoptiles is a unique target for auxin in elongation growth. The following evidence indicates that the outer epidermis is not the only auxin-responsive cell layer in either Avena sativa L. or Zea mays L. coleoptiles. Coleoptile sections from which the epidermis has been removed by peeling elongate in response to auxin. The magnitude of the response is similar to that of intact sections provided the incubation solution contains both auxin and sucrose. The amount of elongation is independent of the amount of epidermis removed. Sections of oat coleoptiles from which the epidermis has been removed from one side are nearly straight after 22 h in auxin and sucrose, despite extensive growth of the sections. These data indicate that the outer epidermis is not a unique target for auxin in elongation growth, at least in Avena and maize coleoptiles.

Increased Number of Langerhans Cells in the Epidermis of Diabetic Foot Ulcers Correlates with Healing Outcome

PubMed Central

Stojadinovic, Olivera; Yin, Natalie; Lehmann, Janin; Pastar, Irena; Kirsner, Robert S.; Tomic-Canic, Marjana

2015-01-01

Langerhans cells (LCs) are a specialized subset of epidermal dendritic cells. They represent one of the first cells of immunological barrier and play an important role during the inflammatory phase of acute wound healing. Despite considerable progress in our understanding of the immunopathology of diabetes mellitus and its associated co-morbidities such as diabetic foot ulcers (DFUs), considerable gaps in our knowledge exist. In this study, we utilized the human ex vivo wound model and confirmed the increased epidermal LCs at wound edges during early phases of wound healing. Next, we aimed to determine differences in quantity of LCs between normal human and diabetic foot skin and to learn if the presence of LCs correlates with the healing outcome in DFUs. We utilized immunofluorescence to detect CD207+ LCs in specimens from normal and diabetic foot skin and DFU wound edges. Specimens from DFUs were collected at the initial visit and 4 weeks at the time when the healing outcome was determined. DFUs that decreased in size by >50% were considered to be healing, while DFUs with a size reduction of <50% were considered non-healing. Quantitative assessment of LCs showed a higher number of LCs in healing when compared to non–healing DFU’s. Our findings provide evidence that LCs are present in higher number in diabetic feet than normal foot skin. Healing DFUs show a higher number of LCs compared to non-healing DFUs. These findings indicate that the epidermal immune barrier plays an important role in the DFU healing outcome and may offer new therapeutic avenues targeting LC in non-healing DFUs. PMID:24277309

In Vivo Multiphoton Microscopy for Investigating Biomechanical Properties of Human Skin.

PubMed

Liang, Xing; Graf, Benedikt W; Boppart, Stephen A

2011-06-01

The biomechanical properties of living cells depend on their molecular building blocks, and are important for maintaining structure and function in cells, the extracellular matrix, and tissues. These biomechanical properties and forces also shape and modify the cellular and extracellular structures under stress. While many studies have investigated the biomechanics of single cells or small populations of cells in culture, or the properties of organs and tissues, few studies have investigated the biomechanics of complex cell populations in vivo. With the use of advanced multiphoton microscopy to visualize in vivo cell populations in human skin, the biomechanical properties are investigated in a depth-dependent manner in the stratum corneum and epidermis using quasi-static mechanical deformations. A 2D elastic registration algorithm was used to analyze the images before and after deformation to determine displacements in different skin layers. In this feasibility study, the images and results from one human subject demonstrate the potential of the technique for revealing differences in elastic properties between the stratum corneum and the rest of the epidermis. This interrogational imaging methodology has the potential to enable a wide range of investigations for understanding how the biomechanical properties of in vivo cell populations influence function in health and disease.

Effects of glyceryl glucoside on AQP3 expression, barrier function and hydration of human skin.

PubMed

Schrader, A; Siefken, W; Kueper, T; Breitenbach, U; Gatermann, C; Sperling, G; Biernoth, T; Scherner, C; Stäb, F; Wenck, H; Wittern, K-P; Blatt, T

2012-01-01

Aquaporins (AQPs) present in the epidermis are essential hydration-regulating elements controlling cellular water and glycerol transport. In this study, the potential of glyceryl glucoside [GG; alpha-D-glucopyranosyl-alpha-(1->2)-glycerol], an enhanced glycerol derivative, to increase the expression of AQP3 in vitro and ex vivo was evaluated. In vitro studies with real-time RT-PCR and FACS measurements were performed to test the induction by GG (3% w/v) of AQP3 mRNA and protein in cultured human keratinocytes. GG-containing formulations were applied topically to volunteer subjects and suction blister biopsies were analyzed to assess whether GG (5%) could penetrate the epidermis of intact skin, and subsequently upregulate AQP3 mRNA expression and improve barrier function. AQP3 mRNA and protein levels were significantly increased in cultured human keratinocytes. In the studies on volunteer subjects, GG significantly increased AQP3 mRNA levels in the skin and reduced transepidermal water loss compared with vehicle-controlled areas. GG promotes AQP3 mRNA and protein upregulation and improves skin barrier function, and may thus offer an effective treatment option for dehydrated skin. Copyright © 2012 S. Karger AG, Basel.

Epidermal Expression and Regulation of Interleukin-33 during Homeostasis and Inflammation: Strong Species Differences.

PubMed

Sundnes, Olav; Pietka, Wojciech; Loos, Tamara; Sponheim, Jon; Rankin, Andrew L; Pflanz, Stefan; Bertelsen, Vibeke; Sitek, Jan C; Hol, Johanna; Haraldsen, Guttorm; Khnykin, Denis

2015-07-01

IL-33 is a novel IL-1 family member with a putative role in inflammatory skin disorders and a complex biology. Therefore, recent conflicting data regarding its function in experimental models justify a close assessment of its tissue expression and regulation. Indeed, we report here that there are strong species differences in the expression and regulation of epidermal IL-33. In murine epidermis, IL-33 behaved similar to an alarmin, being constitutively expressed in keratinocyte nuclei and rapidly lost during acute inflammation. By contrast, human and porcine IL-33 were weakly expressed or absent in keratinocytes of noninflamed skin but induced during acute inflammation. To this end, we observed that expression of IL-33 in human keratinocytes but not murine keratinocytes was strongly induced by IFN-γ, and this upregulation completely depended on the presence of EGFR ligands. Accordingly, IFN-γ increased the expression of IL-33 in the basal layers of the epidermis in human ex vivo skin cultures only, despite good evidence of IFN-γ activity in cultures from both species. Together these findings demonstrate that a full understanding of IL-33 function in clinical settings must take species-specific differences into account.

Skin permeation and antioxidant efficacy of topically applied resveratrol.

PubMed

Alonso, Cristina; Martí, M; Barba, C; Carrer, V; Rubio, L; Coderch, L

2017-08-01

The permeation of resveratrol was assessed by in vitro and in vivo experiments 24 h after topical administration. The in vitro profile of resveratrol was assessed by Raman spectroscopy. Human skin permeation was analysed in vivo by the tape stripping method with the progressive removal of the stratum corneum layers using adhesive tape strips. Moreover, the free radical scavenging activity of resveratrol after its topical application was determined using the DPPH assay. The Raman spectra indicated that the topically applied resveratrol penetrates deep into the skin. The results showed high amounts of resveratrol in the different stratum corneum layers close to the surface and a constant lower amount in the upper layers of the viable epidermis. The concentration of resveratrol present in the outermost stratum corneum layers was obtained by tape stripping after in vivo application. The results demonstrated that resveratrol mainly remained in the human stratum corneum layers. After topical application, resveratrol maintained its antiradical activity. The antioxidant efficacy of the compound was higher in the inner layers of the stratum corneum. As these results have demonstrated, topically applied resveratrol reinforces the antioxidant system of the stratum corneum and provides an efficient means of increasing the tissue levels of antioxidants in the human epidermis.

Skin and Eye Irritation Assessment of Oil Palm ( Elaeis guineensis) Leaf Extract for Topical Application.

PubMed

Yusof, Nor Zuliana; Abd Gani, Siti Salwa; Azizul Hasan, Zafarizal Aldrin; Idris, Zainab

2018-01-01

Many types of phytochemicals have been found to be present in oil palm leaf and could potentially be used as functional ingredients for skincare product. However, as of today, there is no published report on hazard identification and safety assessment of oil palm ( Elaeis guineensis) leaf extract (OPLE), particularly on skin and eye irritation. In this study, potential hazard of OPLE on skin and eye irritation was evaluated as an initial step to the safety assessment of OPLE. In vitro cell viability study of OPLE on normal human dermal fibroblasts showed that OPLE was nontoxic to the cells with percentage viability more than 90% after 24 and 48 hours of incubation. Skin irritation potential of OPLE was evaluated using in vitro SkinEthic reconstructed human epidermis (RHE) model (Organization for Economic Cooperation and Development [OECD] Test Guideline 439, 2015), while eye irritation potential was evaluated using in vitro SkinEthic Human corneal epithelium (HCE) model (OECD test guideline 492, 2017). Hazard identification results showed that OPLE at 1%, 5%, and 10% (wt/wt) was classified as nonirritant to the skin and eye where mean tissue viabilities of SkinEthic RHE and SkinEthic HCE were more than 50% and 60%, respectively. Therefore, we recommend a further safety assessment, such as human patch testing, to confirm the nonirritant of OPLE.

[Morphological characteristic of Langerhans cells from the human epidermis in case of general hypothermia].

PubMed

Stefanenko, E V; Miadelets, O D; Kukhnovets, O A; Miadelets, V O

2009-01-01

The objective of this work was to study morphological changes in the Langerhans cells of epidermis and epithelium of hair follicles from subjects who died as a result of general hypothermia. A total of 105 cadaveric skin samples from subjects of either gender aged from 19 to 83 years were available for analysis. Postmortem examination 1-2 days after death was performed at the Department of Forensic Medical Examination for the Vitebsk region. Skin samples were frozen in liquid nitrogen and studied as cryostat sections. Langerhans cells were detected using the ATPase assay as described by Wachstein and Meisel and modified by Robins and Brendon. The Langerhans cells of subjects who died from general hypothermia were shown to undergo marked morphological changes. Moreover, their number significantly decreased as a result of disintegration and transformation into fine-grain material. Surviving cells lost many of their outgrowths and exhibited enhanced ATPase activity in pericarion. The Langerhans cells from dorsal and ventral skin as well as from interfollicular epidermis and the outer sheath of hair follicles underwent virtually identical changes. A unique morphological feature of the skin in those who died from general hypothermia was formation of intraepidermal, subepidermal, and dermal blisters.

Xenobiotic metabolism capacities of human skin in comparison with a 3D-epidermis model and keratinocyte-based cell culture as in vitro alternatives for chemical testing: phase II enzymes.

PubMed

Götz, Christine; Pfeiffer, Roland; Tigges, Julia; Ruwiedel, Karsten; Hübenthal, Ulrike; Merk, Hans F; Krutmann, Jean; Edwards, Robert J; Abel, Josef; Pease, Camilla; Goebel, Carsten; Hewitt, Nicola; Fritsche, Ellen

2012-05-01

The 7th Amendment to the EU Cosmetics Directive prohibits the use of animals in cosmetic testing for certain endpoints, such as genotoxicity. Therefore, skin in vitro models have to replace chemical testing in vivo. However, the metabolic competence neither of human skin nor of alternative in vitro models has so far been fully characterized, although skin is the first-pass organ for accidentally or purposely (cosmetics and pharmaceuticals) applied chemicals. Thus, there is an urgent need to understand the xenobiotic-metabolizing capacities of human skin and to compare these activities to models developed to replace animal testing. We have measured the activity of the phase II enzymes glutathione S-transferase, UDP-glucuronosyltransferase and N-acetyltransferase in ex vivo human skin, the 3D epidermal model EpiDerm 200 (EPI-200), immortalized keratinocyte-based cell lines (HaCaT and NCTC 2544) and primary normal human epidermal keratinocytes. We show that all three phase II enzymes are present and highly active in skin as compared to phase I. Human skin, therefore, represents a more detoxifying than activating organ. This work systematically compares the activities of three important phase II enzymes in four different in vitro models directly to human skin. We conclude from our studies that 3D epidermal models, like the EPI-200 employed here, are superior over monolayer cultures in mimicking human skin xenobiotic metabolism and thus better suited for dermatotoxicity testing. © 2012 John Wiley & Sons A/S.

The relationship between protease/anti-protease profile, angiogenesis and re-epithelialisation in acute burn wounds.

PubMed

Caulfield, Robert H; Tyler, Michael P H; Austyn, Jon M; Dziewulski, Peter; McGrouther, Duncan A

2008-06-01

In the management of partial thickness burns, it is difficult to balance between conservative management and surgical intervention. Our hypothesis was that a triangular relationship exists between protease/anti-protease profile at the burn wound surface, angiogenesis and re-epithelialisation. By manipulation of the biochemical profile at the wound level, we determined to affect the nature and extent of angiogenesis and resulting re-epithelialisation. We performed a randomised longitudinal observational study on partial thickness burns in adult patients presenting to two regional burns units. Our results demonstrated that a high-protease wound environment is associated with lower levels of the angiogenic factor VEGF, a lower more uniform change in wound bloodflow and a uniform well healed wound with an architecturally normal epidermis. In addition, we found that a low protease wound environment is associated with higher levels of the angiogenic factor VEGF, a higher wound bloodflow throughout the wound healing period and a more chaotic, hypercellular, overkeratinised, and chaotic thickened epidermis.

Variability of hair coat and skin traits as related to adaptation in Criollo Limonero cattle.

PubMed

Landaeta-Hernández, Antonio; Zambrano-Nava, Sunny; Hernández-Fonseca, Juan P; Godoy, Rosario; Calles, Marcos; Iragorri, José L; Añez, Lauderys; Polanco, Miguel; Montero-Urdaneta, Merilio; Olson, Tim

2011-03-01

The variation in hair coat and skin histology traits of Criollo Limonero cattle was analyzed using 213 Criollo Limonero females. Skin biopsies were obtained from slick-haired (N=16) and normal-haired (N=14) animals. Measured traits included hair length (HL), color coat (CC), number of hair follicles per square centimeter (NHF), sweat glands per square centimeter (NSG), sweat glands size (SGS), sebaceous glands per square centimeter (NSBG), blood vessels per square centimeter (NBV), and thickness of epidermis (TE). Hair length differed (P<0.001) between slick- and normal-haired animals (4.9 ± 0.12 vs 10.9 ± 0.20, respectively). Differences (P<0.01) in CC (Bayo = 144/67.6% vs Red = 69/32.4%) and HL (slick-haired = 199/93.4% vs normal-haired = 14/6.5%) were found. Distribution of slick- and normal-haired animals differed (P<0.01) between bayo-coated and red-coated (139/62.2% vs 9/4.2%; respectively). Most (P<0.05) red-coated animals belonged to a single family. No differences (P>0.05) were found between slick-haired and normal-haired animals in NHF (637 ± 164 vs 587 ± 144, respectively), NSG (556 ± 134 vs 481 ± 118, respectively), NSBG (408 ± 87 vs 366 ± 77, respectively), NBV (1628 ± 393 vs 1541 ± 346, respectively), and TE (1.24 ± 0.14 vs 1.32 ± 0.12, respectively). However, SGS was greater (P<0.01) in slick-haired than normal-haired animals. In conclusion, Criollo Limonero cattle are predominantly bayo-coated, slick-haired, with a reduced number of hair follicles relative to Zebu cattle, sweat and sebaceous glands in proportion to hair follicle numbers, and with a high blood flow irrigating the skin. There is a sub-group of red-coated animals with yellow or cream skin, thicker epidermis, and with a higher frequency of normal-haired animals. It appears that the slick hair gene has been favored by natural selection in this breed.

Distribution of caspase-14 in epidermis and hair follicles is evolutionarily conserved among mammals.

PubMed

Alibardi, Lorenzo; Tschachler, Erwin; Eckhart, Leopold

2005-10-01

Caspase-14, a member of the caspase family of cysteine proteases, is almost exclusively expressed in the epidermis. Studies on human and mouse cells and tissues have implicated caspase-14 in terminal differentiation of epidermal keratinocytes and in the formation of the stratum corneum. Here we investigated evolutionary aspects of the role of caspase-14 by analyzing its distribution in the epidermis and hair follicles of representative species of placental mammals, marsupials, and monotremes. Immunocytochemical staining showed that caspase-14 is consistently expressed in the granular and corneous layer of the epidermis of all mammalian species investigated. Ultrastructural analysis using gold-labeled anticaspase-14 antibodies revealed that caspase-14 is associated preferentially with keratin bundles and amorphous material of keratohyalin granules, but is also present in nuclei of transitional cells of the granular layer and in corneocytes. In hair follicles, caspase-14 was diffusely present in cornifying cells of the outer root sheath, in the companion layer, and, most abundantly, in the inner root sheath of all mammalian species here analyzed. In Henle and Huxley layers of the inner root sheath, labeling was seen in nuclei and, more diffusely, among trichohyalin granules of cornifying cells. In summary, the tissue expression pattern and the intracellular localization of caspase-14 are highly conserved among diverse mammalian species, suggesting that this enzyme is involved in a molecular process that appeared early in the evolution of mammalian skin. The association of caspase-14 with keratohyalin and trichohyalin granules may indicate a specific role of caspase-14 in the maturation of these keratinocyte-specific structures.

S100A8 and S100A9 Are Induced by Decreased Hydration in the Epidermis and Promote Fibroblast Activation and Fibrosis in the Dermis.

PubMed

Zhong, Aimei; Xu, Wei; Zhao, Jingling; Xie, Ping; Jia, Shengxian; Sun, Jiaming; Galiano, Robert D; Mustoe, Thomas A; Hong, Seok J

2016-01-01

The most critical function of the epidermis is to prevent water loss and maintain skin homeostasis. Disruption of the functional skin barrier causes delayed wound healing, hypertrophic scarring, and many skin diseases. Herein, we show that reduced hydration increases the expression of S100 protein family members, S100A8/S100A9, in stratified keratinocyte culture and human ex vivo skin culture. Immunohistological analyses show that S100A8/A9 are highly expressed in the epidermis of human hypertrophic scar and keloid tissues. Reduced hydration demonstrates activation of fibroblasts in the keratinocyte-fibroblast co-culture. In contrast, knockdown of S100A8 or S100A9 by RNA interference in keratinocytes failed to activate fibroblasts. Pretreatment with pharmacological blockers of S100A8/A9 receptors, Toll-like receptor 4 and receptor for advanced glycation end products, inhibits fibroblast activation induced by recombinant S100A8/A9 proteins. Moreover, we observe that local delivery of S100A8 protein results in a marked increase in hypertrophic scarring in the in vivo rabbit ear scar model. Our results indicate that hydration status promotes fibroblast activation and fibrosis by directly affecting the expression of inflammatory signaling in keratinocytes, thereby strongly suggesting S100A8/A9 to be novel targets in preventing scarring. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Loss of Desmocollin 3 in Skin Tumor Development and Progression

PubMed Central

Chen, Jiangli; O’Shea, Charlene; Fitzpatrick, James E.; Koster, Maranke I.; Koch, Peter J.

2011-01-01

Desmocollin 3 (DSC3) is a desmosomal cadherin that is required for maintaining cell adhesion in the epidermis as demonstrated by the intra-epidermal blistering observed in Dsc3 null skin. Recently, it has been suggested that deregulated expression of DSC3 occurs in certain human tumor types. It is not clear whether DSC3 plays a role in the development or progression of cancers arising in stratified epithelia such as the epidermis. To address this issue, we generated a mouse model in which Dsc3 expression is ablated in K-Ras oncogene-induced skin tumors. Our results demonstrate that loss of Dsc3 leads to an increase in K-Ras induced skin tumors. We hypothesize that acantholysis-induced epidermal hyperplasia in the Dsc3 null epidermis facilitates Ras-induced tumor development. Further, we demonstrate that spontaneous loss of DSC3 expression is a common occurrence during human and mouse skin tumor progression. This loss occurs in tumor cells invading the dermis. Interestingly, other desmosomal proteins are still expressed in tumor cells that lack DSC3, suggesting a specific function of DSC3 loss in tumor progression. While loss of DSC3 on the skin surface leads to epidermal blistering, it does not appear to induce loss of cell-cell adhesion in tumor cells invading the dermis, most likely due to a protection of these cells within the dermis from mechanical stress. We thus hypothesize that DSC3 can contribute to the progression of tumors both by cell adhesion-dependent (skin surface) and likely by cell adhesion-independent (invading tumor cells) mechanisms. PMID:21681825

Potential of EPR spin-trapping to investigate in situ free radicals generation from skin allergens in reconstructed human epidermis: cumene hydroperoxide as proof of concept.

PubMed

Kuresepi, Salen; Vileno, Bertrand; Turek, Philippe; Lepoittevin, Jean-Pierre; Giménez-Arnau, Elena

2018-02-01

The first step in the development of skin sensitisation to a chemical, and in the elicitation of further allergic contact dermatitis (ACD), is the binding of the allergen to skin proteins after penetrating into the epidermis. The so-formed antigenic adduct is then recognised by the immune system as foreign to the body. Sensitising organic hydroperoxides derived from autoxidation of natural terpenes are believed to form antigens through radical-mediated mechanisms, although this has not yet been established. So far, in vitro investigations on reactive radical intermediates derived from these skin sensitisers have been conducted in solution, yet with experimental conditions being far away from real-life sensitisation. Herein, we report for the first time, the potential use of EPR spin-trapping to study the in situ generation of free radicals derived from cumene hydroperoxide CumOOH in a 3D reconstructed human epidermis (RHE) model, thus much closer to what may happen in vivo. Among the undesirable effects associated with dermal exposure to CumOOH, it is described to cause allergic and irritant dermatitis, being reported as a significant sensitiser. We considered exploiting the usage of spin-trap DEPMPO as an extensive view of all sort of radicals derived from CumOOH were observed all at once in solution. We showed that in the Episkin TM RHE model, both by incubating in the assay medium and by topical application, carbon radicals are mainly formed by redox reactions suggesting the key role of CumOOH-derived carbon radicals in the antigen formation process.

Nuclear DNA damage-triggered NLRP3 inflammasome activation promotes UVB-induced inflammatory responses in human keratinocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasegawa, Tatsuya, E-mail: tatsuya.hasegawa@to.shiseido.co.jp; Nakashima, Masaya; Suzuki, Yoshiharu

Ultraviolet (UV) radiation in sunlight can result in DNA damage and an inflammatory reaction of the skin commonly known as sunburn, which in turn can lead to cutaneous tissue disorders. However, little has been known about how UV-induced DNA damage mediates the release of inflammatory mediators from keratinocytes. Here, we show that UVB radiation intensity-dependently increases NLRP3 gene expression and IL-1β production in human keratinocytes. Knockdown of NLRP3 with siRNA suppresses UVB-induced production of not only IL-1β, but also other inflammatory mediators, including IL-1α, IL-6, TNF-α, and PGE{sub 2}. In addition, inhibition of DNA damage repair by knockdown of XPA,more » which is a major component of the nucleotide excision repair system, causes accumulation of cyclobutane pyrimidine dimer (CPD) and activation of NLRP3 inflammasome. In vivo immunofluorescence analysis confirmed that NLRP3 expression is also elevated in UV-irradiated human epidermis. Overall, our findings indicate that UVB-induced DNA damage initiates NLRP3 inflammasome activation, leading to release of various inflammatory mediators from human keratinocytes. - Highlights: • UVB radiation induces NLRP3 inflammasome activation in human keratinocytes. • NLRP3 knockdown suppresses production of UVB-induced inflammatory mediators. • UVB-induced DNA damage triggers NLRP3 inflammasome activation. • NLRP3 expression in human epidermis is elevated in response to UV radiation.« less

Materials and optimized designs for human-machine interfaces via epidermal electronics.

PubMed

Jeong, Jae-Woong; Yeo, Woon-Hong; Akhtar, Aadeel; Norton, James J S; Kwack, Young-Jin; Li, Shuo; Jung, Sung-Young; Su, Yewang; Lee, Woosik; Xia, Jing; Cheng, Huanyu; Huang, Yonggang; Choi, Woon-Seop; Bretl, Timothy; Rogers, John A

2013-12-17

Thin, soft, and elastic electronics with physical properties well matched to the epidermis can be conformally and robustly integrated with the skin. Materials and optimized designs for such devices are presented for surface electromyography (sEMG). The findings enable sEMG from wide ranging areas of the body. The measurements have quality sufficient for advanced forms of human-machine interface. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Targeted disruption of glutathione peroxidase 4 (GPx4) in mouse skin epithelial cells impairs postnatal hair follicle morphogenesis that is partially rescued through inhibition of COX-2

PubMed Central

Sengupta, Aniruddha; Lichti, Ulrike F.; Carlson, Bradley A.; Cataisson, Christophe; Ryscavage, Andrew O.; Mikulec, Carol; Conrad, Marcus; Fischer, Susan M.; Hatfield, Dolph L.; Yuspa, Stuart H.

2013-01-01

Selenoproteins are essential molecules for the mammalian antioxidant network. We previously demonstrated that targeted loss of all selenoproteins in mouse epidermis disrupted skin and hair development and caused premature death. In the current study we targeted specific selenoproteins for epidermal deletion to determine whether similar phenotypes developed. Keratinocyte-specific knockout mice lacking either the glutathione peroxidase 4 (GPx4) or thioredoxin reductase 1 (TR1) gene were generated by cre-lox technology using K14-cre. TR1 knockout mice had a normal phenotype in resting skin while GPx4 loss in epidermis caused epidermal hyperplasia, dermal inflammatory infiltrate, dysmorphic hair follicles and alopecia in perinatal mice. Unlike epidermal ablation of all selenoproteins, mice ablated for GPx4 recovered after 5 weeks and had a normal lifespan. GPx1 and TR1 were upregulated in the skin and keratinocytes of GPx4 knockout mice. GPx4 deletion reduces keratinocyte adhesion in culture and increases lipid peroxidation and COX-2 levels in cultured keratinocytes and whole skin. Feeding a COX-2 inhibitor to nursing mothers partially prevents development of the abnormal skin phenotype in knockout pups. These data link the activity of cutaneous GPx4 to the regulation of COX-2 and hair follicle morphogenesis and provide insight into the function of individual selenoprotein activity in maintaining cutaneous homeostasis. PMID:23364477

Normal and PPP-affected palmoplantar sweat gland express neuroendocrine markers chromogranins and synaptophysin differently.

PubMed

Hagforsen, Eva; Michaëlsson, Gerd; Stridsberg, Mats

2010-11-01

Earlier findings indicate the acrosyringium as the target for the inflammation in the chronic and intensely inflammatory skin disease palmoplantar pustulosis (PPP). The sweat gland apparatus seems to be an immune-competent structure that probably contributes to the defence of the skin. Furthermore, the sweat gland and duct may be a hitherto unrecognized neuroendocrine organ because it expresses cholineacetyl-transferase and acetylcholinesterase, nicotinic receptors, beta-adrenergic and angiotensin receptors. The aim of this study was to obtain further information about neuroendocrine properties of the sweat gland apparatus by examining the expression of common neuroendocrine markers synaptophysin and chromogranins A and B in healthy palmar skin and in PPP skin. Synaptophysin and chromogranins were expressed in the sweat glands and ducts with some variation in the pattern and intensity of the expression. In PPP skin the expression differed, being higher and lower, depending on the part of the sweat duct. Chromogranins were further expressed in the epidermis, endothelium and inflammatory cells, but its intensity was weaker in epidermis than in the sweat gland apparatus. In most cases, chromogranins in epidermis in involved PPP were weakly expressed compared to healthy controls. The presence of synaptophysin and chromogranins in palmoplantar skin may have marked neuroendocrine effects, and the palmoplantar skin is likely to have important neuroimmuno-endocrine properties. Moreover, the altered chromogranin expression in PPP skin might influence both the neuroendocrine and neuroimmunologic properties of palmoplantar skin in these patients. These results indicate important neuroendocrine properties of the palmoplantar skin.

The Toll pathway is required in the epidermis for muscle development in the Drosophila embryo

NASA Technical Reports Server (NTRS)

Halfon, M. S.; Keshishian, H.

1998-01-01

The Toll signaling pathway functions in several Drosophila processes, including dorsal-ventral pattern formation and the immune response. Here, we demonstrate that this pathway is required in the epidermis for proper muscle development. Previously, we showed that the zygotic Toll protein is necessary for normal muscle development; in the absence of zygotic Toll, close to 50% of hemisegments have muscle patterning defects consisting of missing, duplicated and misinserted muscle fibers (Halfon, M.S., Hashimoto, C., and Keshishian, H., Dev. Biol. 169, 151-167, 1995). We have now also analyzed the requirements for easter, spatzle, tube, and pelle, all of which function in the Toll-mediated dorsal-ventral patterning pathway. We find that spatzle, tube, and pelle, but not easter, are necessary for muscle development. Mutations in these genes give a phenotype identical to that seen in Toll mutants, suggesting that elements of the same pathway used for Toll signaling in dorsal-ventral development are used during muscle development. By expressing the Toll cDNA under the control of distinct Toll enhancer elements in Toll mutant flies, we have examined the spatial requirements for Toll expression during muscle development. Expression of Toll in a subset of epidermal cells that includes the epidermal muscle attachment cells, but not Toll expression in the musculature, is necessary for proper muscle development. Our results suggest that signals received by the epidermis early during muscle development are an important part of the muscle patterning process.

p53 and TAp63 Promote Keratinocyte Proliferation and Differentiation in Breeding Tubercles of the Zebrafish

PubMed Central

Fischer, Boris; Metzger, Manuel; Richardson, Rebecca; Knyphausen, Philipp; Ramezani, Thomas; Franzen, Rainer; Schmelzer, Elmon; Bloch, Wilhelm; Carney, Thomas J.; Hammerschmidt, Matthias

2014-01-01

p63 is a multi-isoform member of the p53 family of transcription factors. There is compelling genetic evidence that ΔNp63 isoforms are needed for keratinocyte proliferation and stemness in the developing vertebrate epidermis. However, the role of TAp63 isoforms is not fully understood, and TAp63 knockout mice display normal epidermal development. Here, we show that zebrafish mutants specifically lacking TAp63 isoforms, or p53, display compromised development of breeding tubercles, epidermal appendages which according to our analyses display more advanced stratification and keratinization than regular epidermis, including continuous desquamation and renewal of superficial cells by derivatives of basal keratinocytes. Defects are further enhanced in TAp63/p53 double mutants, pointing to partially redundant roles of the two related factors. Molecular analyses, treatments with chemical inhibitors and epistasis studies further reveal the existence of a linear TAp63/p53->Notch->caspase 3 pathway required both for enhanced proliferation of keratinocytes at the base of the tubercles and their subsequent differentiation in upper layers. Together, these studies identify the zebrafish breeding tubercles as specific epidermal structures sharing crucial features with the cornified mammalian epidermis. In addition, they unravel essential roles of TAp63 and p53 to promote both keratinocyte proliferation and their terminal differentiation by promoting Notch signalling and caspase 3 activity, ensuring formation and proper homeostasis of this self-renewing stratified epithelium. PMID:24415949

Identification of heparin-binding EGF-like growth factor as a target in intercellular regulation of epidermal basal cell growth by suprabasal retinoic acid receptors.

PubMed Central

Xiao, J H; Feng, X; Di, W; Peng, Z H; Li, L A; Chambon, P; Voorhees, J J

1999-01-01

The role of retinoic acid receptors (RARs) in intercellular regulation of cell growth was assessed by targeting a dominant-negative RARalpha mutant (dnRARalpha) to differentiated suprabasal cells of mouse epidermis. dnRARalpha lacks transcriptional activation but not DNA-binding and receptor dimerization functions. Analysis of transgenic mice revealed that dnRARalpha dose-dependently impaired induction of basal cell proliferation and epidermal hyperplasia by all-trans RA (tRA). dnRARalpha formed heterodimers with endogenous retinoid X receptor-alpha (RXRalpha) over RA response elements in competition with remaining endogenous RARgamma-RXRalpha heterodimers, and dose-dependently impaired retinoid-dependent gene transcription. To identify genes regulated by retinoid receptors and involved in cell growth control, we analyzed the retinoid effects on expression of the epidermal growth factor (EGF) receptor, EGF, transforming growth factor-alpha, heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin genes. In normal epidermis, tRA rapidly and selectively induced expression of HB-EGF but not the others. This induction occurred exclusively in suprabasal cells. In transgenic epidermis, dnRARalpha dose-dependently inhibited tRA induction of suprabasal HB-EGF and subsequent basal cell hyperproliferation. Together, our observations suggest that retinoid receptor heterodimers located in differentiated suprabasal cells mediate retinoid induction of HB-EGF, which in turn stimulates basal cell growth via intercellular signaling. These events may underlie retinoid action in epidermal regeneration during wound healing. PMID:10075925

Epidermal segmentation in high-definition optical coherence tomography.

PubMed

Li, Annan; Cheng, Jun; Yow, Ai Ping; Wall, Carolin; Wong, Damon Wing Kee; Tey, Hong Liang; Liu, Jiang

2015-01-01

Epidermis segmentation is a crucial step in many dermatological applications. Recently, high-definition optical coherence tomography (HD-OCT) has been developed and applied to imaging subsurface skin tissues. In this paper, a novel epidermis segmentation method using HD-OCT is proposed in which the epidermis is segmented by 3 steps: the weighted least square-based pre-processing, the graph-based skin surface detection and the local integral projection-based dermal-epidermal junction detection respectively. Using a dataset of five 3D volumes, we found that this method correlates well with the conventional method of manually marking out the epidermis. This method can therefore serve to effectively and rapidly delineate the epidermis for study and clinical management of skin diseases.

SUNLIGHT AS A FACTOR INFLUENCING THE THICKNESS OF EPIDERMIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freeman, R.G.; Cockerell, E.G.; Armstrong, J.

Measurements of epidermal thickness were made on 28 human volunteers. Shortening of rete ridges was found in exposed white skin but was not seen in unexposed skin nor in Negroes. Differences in epidermal thickness related to age, sex, complexion, or variation in sunlight exposure were not statistically significant. (P.C.H.)

Automatic characterization and segmentation of human skin using three-dimensional optical coherence tomography

NASA Astrophysics Data System (ADS)

Hori, Yasuaki; Yasuno, Yoshiaki; Sakai, Shingo; Matsumoto, Masayuki; Sugawara, Tomoko; Madjarova, Violeta; Yamanari, Masahiro; Makita, Shuichi; Yasui, Takeshi; Araki, Tsutomu; Itoh, Masahide; Yatagai, Toyohiko

2006-03-01

A set of fully automated algorithms that is specialized for analyzing a three-dimensional optical coherence tomography (OCT) volume of human skin is reported. The algorithm set first determines the skin surface of the OCT volume, and a depth-oriented algorithm provides the mean epidermal thickness, distribution map of the epidermis, and a segmented volume of the epidermis. Subsequently, an en face shadowgram is produced by an algorithm to visualize the infundibula in the skin with high contrast. The population and occupation ratio of the infundibula are provided by a histogram-based thresholding algorithm and a distance mapping algorithm. En face OCT slices at constant depths from the sample surface are extracted, and the histogram-based thresholding algorithm is again applied to these slices, yielding a three-dimensional segmented volume of the infundibula. The dermal attenuation coefficient is also calculated from the OCT volume in order to evaluate the skin texture. The algorithm set examines swept-source OCT volumes of the skins of several volunteers, and the results show the high stability, portability and reproducibility of the algorithm.

Accelerated healing of skin burns by anti-Gal/alpha-gal liposomes interaction.

PubMed

Galili, Uri; Wigglesworth, Kim; Abdel-Motal, Ussama M

2010-03-01

Topical application of alpha-gal liposomes on burns results in rapid local recruitment of neutrophils and macrophages. Recruited macrophages are pivotal for healing of burns because they secrete cytokines/growth factors that induce epidermis regeneration and tissue repair. alpha-Gal liposomes have glycolipids with alpha-gal epitopes (Galalpha1-3Galbeta1-4GlcNAc-R) which bind anti-Gal, the most abundant natural antibody in humans constituting approximately 1% of immunoglobulins. Interaction of alpha-gal liposomes with anti-Gal within the fluid film formed on burns, activates complement and generates chemotactic complement cleavage peptides which effectively recruit neutrophils and macrophages. Anti-Gal IgG coating alpha-gal liposomes further binds to Fcgamma receptors on macrophages and activates them to secrete cytokines/growth factors. Efficacy of alpha-gal liposomes treatment in accelerating burn healing is demonstrated in the experimental model of alpha1,3galactosyltransferase knockout mice. These mice are the only available nonprimate mammals that can produce anti-Gal in titers similar to those in humans. Pairs of burns in mice were covered either with a spot bandage coated with 10mg alpha-gal liposomes, or with a control spot bandage coated with saline. On Day 3 post-treatment, the alpha-gal liposomes treated burns contained approximately 5-fold as many neutrophils as control burns, whereas macrophages were found only in alpha-gal liposomes treated burns. On Day 6, 50-100% of the surface area of alpha-gal liposomes treated burns were covered with regenerating epidermis (re-epithelialization), whereas almost no epidermis was found in control burns. The extensive recruitment of macrophages by anti-Gal/alpha-gal liposomes interaction was further demonstrated in vivo with polyvinyl alcohol (PVA) sponge discs containing alpha-gal liposomes, implanted subcutaneously. Since anti-Gal is abundant in all humans, it is suggested that treatment with alpha-gal liposomes will be effective also in patients with burns and other skin wounds. Copyright (c) 2009 Elsevier Ltd and ISBI. All rights reserved.

Evaluation of Hypoxia Inducible Factor-1α and Glucose Transporter-1 Expression in Non Melanoma Skin Cancer: An Immunohistochemical Study

PubMed Central

Seleit, Iman; Bakry, Ola Ahmed; Ragab, Rania Abdel Aziz; Al-Shiemy, shimaa Ahmed

2017-01-01

Introduction Hypoxia Inducible Factor-1 (HIF-1) is a mediator enabling cell adaptation to hypoxia. It plays its role mainly through transcription of many target genes including Glucose Transporter-1 (GLUT-1) gene. Aim The present work aimed at evaluating the pattern and distribution of HIF-1α and GLUT-1 in each case and control. Materials and Methods A case-control and retrospective study was conducted on archival blocks diagnosed from pathology department as, Basal Cell Carcinoma (BCC, 20 cases), cutaneous Squamous Cell Carcinoma (SCC, 20 cases) and 20 normal site-matched skin biopsies from age and gender-matched healthy subjects as a control. Evaluation of both HIF-1α and GLUT1 expression using standard immunohistochemical techniques was performed on cut sections from selected paraffin embedded blocks. Results HIF-1α was expressed in 90%, 35% and 100% of normal skin, BCC and SCC tumour islands respectively. It was up regulated in both BCC and SCC compared with normal skin (p= 0.001, p<0.001 respectively). GLUT-1 was expressed in 100%, 70% and 100% of normal skin, BCC and SCC tumour islands respectively. It was down regulated in Non Melanoma Skin Cancer (NMSC) cases compared with normal skin (p=0.004). HIF-1α and GLUT-1 localization in tumour nests was central, peripheral or central and peripheral. Both HIF-1α and GLUT-1 showed variable expression in stroma, adnexa and inflammatory cells. No significant correlation was found between Histo (H) score or expression percentage values of HIF-1α and those of GLUT-1 in tumour islands or in overlying epidermis either in BCC or SCC. Conclusion HIF-1α may have a role in NMSC pathogenesis through adaptation to hypoxia which results from excessive proliferation. GLUT-1 down regulation in NMSC may be explained by its consumption by proliferating tumour cells. The expression of HIF-1α and GLUT-1 in normal epidermis, stromal and adnexal structures needs further research. PMID:28764171

Efficient Healing Takes Some Nerve: Electrical Stimulation Enhances Innervation in Cutaneous Human Wounds.

PubMed

Emmerson, Elaine

2017-03-01

Cutaneous nerves extend throughout the dermis and epidermis and control both the functional and reparative capacity of the skin. Denervation of the skin impairs cutaneous healing, presenting evidence that nerves provide cues essential for timely wound repair. Sebastian et al. demonstrate that electrical stimulation promotes reinnervation and neural differentiation in human acute wounds, thus accelerating wound repair. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

Multiphoton spectroscopy of human skin in vivo

NASA Astrophysics Data System (ADS)

Breunig, Hans G.; Weinigel, Martin; König, Karsten

2012-03-01

In vivo multiphoton-intensity images and emission spectra of human skin are reported. Optical sections from different depths of the epidermis and dermis have been measured with near-infrared laser-pulse excitation. While the intensity images reveal information on the morphology, the spectra show emission characteristics of main endogenous skin fluorophores like keratin, NAD(P)H, melanin, elastin and collagen as well as of second harmonic generation induced by the excitation-light interaction with the dermal collagen network.

UV-B Radiation Induces Macrophage Migration Inhibitory Factor–Mediated Melanogenesis through Activation of Protease-Activated Receptor-2 and Stem Cell Factor in Keratinocytes

PubMed Central

Enomoto, Akiko; Yoshihisa, Yoko; Yamakoshi, Takako; Ur Rehman, Mati; Norisugi, Osamu; Hara, Hiroshi; Matsunaga, Kenji; Makino, Teruhiko; Nishihira, Jun; Shimizu, Tadamichi

2011-01-01

UV radiation indirectly regulates melanogenesis in melanocytes through a paracrine regulatory mechanism involving keratinocytes. Protease-activated receptor (PAR)-2 activation induces melanosome transfer by increasing phagocytosis of melanosomes by keratinocytes. This study demonstrated that macrophage migration inhibitory factor (MIF) stimulated PAR-2 expression in human keratinocytes. In addition, we showed that MIF stimulated stem cell factor (SCF) release in keratinocytes; however, MIF had no effect on the release of endothelin-1 or prostaglandin E2 in keratinocytes. In addition, MIF had no direct effect on melanin and tyrosinase synthesis in cultured human melanocytes. The effect of MIF on melanogenesis was also examined using a three-dimensional reconstituted human epidermal culture model, which is a novel, commercially available, cultured human epidermis containing functional melanocytes. Migration inhibitory factor induced an increase in melanin content in the epidermis after a 9-day culture period. Moreover, melanin synthesis induced by UV-B stimulation was significantly down-regulated by anti-MIF antibody treatment. An in vivo study showed that the back skin of MIF transgenic mice had a higher melanin content than that of wild-type mice after 12 weeks of UV-B exposure. Therefore, MIF-mediated melanogenesis occurs mainly through the activation of PAR-2 and SCF expression in keratinocytes after exposure to UV-B radiation. PMID:21281800

In vitro activation of the neuro-transduction mechanism in sensitive organotypic human skin model.

PubMed

Martorina, Francesca; Casale, Costantino; Urciuolo, Francesco; Netti, Paolo A; Imparato, Giorgia

2017-01-01

Recent advances in tissue engineering have encouraged researchers to endeavor the production of fully functional three-dimensional (3D) thick human tissues in vitro. Here, we report the fabrication of a fully innervated human skin tissue in vitro that recapitulates and replicates skin sensory function. Previous attempts to innervate in vitro 3D skin models did not demonstrate an effective functionality of the nerve network. In our approach, we initially engineer functional human skin tissue based on fibroblast-generated dermis and differentiated epidermis; then, we promote rat dorsal root ganglion (DRG) neurons axon ingrowth in the de-novo developed tissue. Neurofilaments network infiltrates the entire native dermis extracellular matrix (ECM), as demonstrated by immunofluorescence and second harmonic generation (SHG) imaging. To prove sensing functionality of the tissue, we use topical applications of capsaicin, an agonist of transient receptor protein-vanilloid 1 (TRPV1) channel, and quantify calcium currents resulting from variations of Ca ++ concentration in DRG neurons innervating our model. Calcium currents generation demonstrates functional cross-talking between dermis and epidermis compartments. Moreover, through a computational fluid dynamic (CFD) analysis, we set fluid dynamic conditions for a non-planar skin equivalent growth, as proof of potential application in creating skin grafts tailored on-demand for in vivo wound shape. Copyright © 2016 Elsevier Ltd. All rights reserved.

Skin melanocytes: biology and development

PubMed Central

Wachulska, Małgorzata; Stasiewicz, Aneta; Tymińska, Agata

2013-01-01

In the human skin, melanocytes are present in the epidermis and hair follicles. The basic features of these cells are the ability to melanin production and the origin from neural crest cells. This last element is important because there are other cells able to produce melanin but of different embryonic origin (pigmented epithelium of retina, some neurons, adipocytes). The life cycle of melanocyte consists of several steps including differentiation of melanocyte lineage/s from neural crest, migration and proliferation of melanoblasts, differentiation of melanoblasts into melanocytes, proliferation and maturation of melanocytes at the target places (activity of melanogenic enzymes, melanosome formation and transport to keratinocytes) and eventual cell death (hair melanocytes). Melanocytes of the epidermis and hair are cells sharing some common features but in general they form biologically different populations living in unique niches of the skin. PMID:24278043

Optical coherence tomography demonstrates differential epidermal thinning of human forearm volar skin after 2 weeks application of a topical corticosteroid vs a non-steroidal anti-inflammatory alternative

NASA Astrophysics Data System (ADS)

Lu, Zenghai; Boadi, Joseph; Danby, Simon; Cork, Michael; Matcher, Stephen J.

2013-03-01

The effects on skin of two commercially available topical creams for the treatment of eczema are quantitatively studied using optical coherence tomography. An archetypal corticosteroid (Betamethasone valerate) is compared with a nonsteroidal anti-inflammatory drug (Tacrolimus monohydrate) via left/right comparisons of the epidermal thickness of volar forearm skin on selected volunteers, at baseline and after 14 days of treatment. In 3 of 4 subjects we confirmed previous observations that corticosteroids produce pronounced physical thinning of the epidermis over timescales of a few weeks. In 3 of 4 subjects we further found that Tacrolimus produced no change in epidermal thickness. In one of 4 subjects we found evidence that the epidermis was actually thickened following treatment using Tacrolimus.

Epidermis Microstructure Inspired Graphene Pressure Sensor with Random Distributed Spinosum for High Sensitivity and Large Linearity.

PubMed

Pang, Yu; Zhang, Kunning; Yang, Zhen; Jiang, Song; Ju, Zhenyi; Li, Yuxing; Wang, Xuefeng; Wang, Danyang; Jian, Muqiang; Zhang, Yingying; Liang, Renrong; Tian, He; Yang, Yi; Ren, Tian-Ling

2018-03-27

Recently, wearable pressure sensors have attracted tremendous attention because of their potential applications in monitoring physiological signals for human healthcare. Sensitivity and linearity are the two most essential parameters for pressure sensors. Although various designed micro/nanostructure morphologies have been introduced, the trade-off between sensitivity and linearity has not been well balanced. Human skin, which contains force receptors in a reticular layer, has a high sensitivity even for large external stimuli. Herein, inspired by the skin epidermis with high-performance force sensing, we have proposed a special surface morphology with spinosum microstructure of random distribution via the combination of an abrasive paper template and reduced graphene oxide. The sensitivity of the graphene pressure sensor with random distribution spinosum (RDS) microstructure is as high as 25.1 kPa -1 in a wide linearity range of 0-2.6 kPa. Our pressure sensor exhibits superior comprehensive properties compared with previous surface-modified pressure sensors. According to simulation and mechanism analyses, the spinosum microstructure and random distribution contribute to the high sensitivity and large linearity range, respectively. In addition, the pressure sensor shows promising potential in detecting human physiological signals, such as heartbeat, respiration, phonation, and human motions of a pushup, arm bending, and walking. The wearable pressure sensor array was further used to detect gait states of supination, neutral, and pronation. The RDS microstructure provides an alternative strategy to improve the performance of pressure sensors and extend their potential applications in monitoring human activities.

Expression and localization of peroxisome proliferator-activated receptors and nuclear factor kappaB in normal and lesional psoriatic skin.

PubMed

Westergaard, Majken; Henningsen, Jeanette; Johansen, Claus; Rasmussen, Sofie; Svendsen, Morten Lyhne; Jensen, Uffe Birk; Schrøder, Henrik Daa; Staels, Bart; Iversen, Lars; Bolund, Lars; Kragballe, Knud; Kristiansen, Karsten

2003-11-01

Abnormal epidermal proliferation and differentiation characterize the inflammatory skin disease psoriasis. Here we demonstrate that expression of PPARdelta mRNA and protein is markedly upregulated in psoriatic lesions and that lipoxygenase products accumulating in psoriatic lesions are potent activators of PPARdelta. The expression levels of NF-kappaB p50 and p65 were not significantly altered in lesional compared with nonlesional psoriatic skin. In the basal layer of normal epidermis both p50 and p65 were sequestered in the cytoplasm, whereas p50, but not p65, localized to nuclei in the suprabasal layers, and this distribution was maintained in lesional psoriatic skin. In normal human keratinocytes PPAR agonists neither impaired IL-1beta-induced translocation of p65 nor IL-1beta-induced NF-kappaB DNA binding. We show that PPARdelta physically interacts with the N-terminal Rel homology domain of p65. Irrespective of the presence of agonists none of the PPAR subtypes decreased p65-mediated transactivation in keratinocytes. In contrast p65, but not p50, was a potent repressor of PPAR-mediated transactivation. The p65-dependent repression of PPARdelta- but not PPARalpha- or PPARgamma-mediated transactivation was partially relieved by forced expression of the coactivators p300 or CBP. We suggest that deficient NF-kappaB activation in chronic psoriatic plaques permitting unabated PPARdelta-mediated transactivation contributes to the pathologic phenotype of psoriasis.

In vivo spatial frequency domain spectroscopy of two layer media

NASA Astrophysics Data System (ADS)

Yudovsky, Dmitry; Nguyen, John Quan M.; Durkin, Anthony J.

2012-10-01

Monitoring of tissue blood volume and local oxygen saturation can inform the assessment of tissue health, healing, and dysfunction. These quantities can be estimated from the contribution of oxyhemoglobin and deoxyhemoglobin to the absorption spectrum of the dermis. However, estimation of blood related absorption in skin can be confounded by the strong absorption of melanin in the epidermis and epidermal thickness and pigmentation varies with anatomic location, race, gender, and degree of disease progression. Therefore, a method is desired that decouples the effect of melanin absorption in the epidermis from blood absorption in the dermis for a large range of skin types and thicknesses. A previously developed inverse method based on a neural network forward model was applied to simulated spatial frequency domain reflectance of skin for multiple wavelengths in the near infrared. It is demonstrated that the optical thickness of the epidermis and absorption and reduced scattering coefficients of the dermis can be determined independently and with minimal coupling. Then, the same inverse method was applied to reflectance measurements from a tissue simulating phantom and in vivo human skin. Oxygen saturation and total hemoglobin concentrations were estimated from the volar forearms of weakly and strongly pigmented subjects using a standard homogeneous model and the present two layer model.

Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manwaring, John, E-mail: manwaring.jd@pg.com; Rothe, Helga; Obringer, Cindy

Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passagemore » through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte K{sub m} and V{sub max} values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and C{sub max} was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human skin explants and HaCaT • Systemic metabolism was modeled using hepatocyte cultures. • Toxicokinetically relevant parameters were applied to estimate systemic exposure. • There was a good agreement between in vitro and in vivo data.« less

In vitro study of the effects of ELF electric fields on gene expression in human epidermal cells.

PubMed

Collard, Jean-Francois; Mertens, Benjamin; Hinsenkamp, Maurice

2011-01-01

An acceleration of differentiation, at the expense of proliferation, is observed after exposure of various biological models to low frequency and low amplitude electric and electromagnetic fields. Following these results showing significant modifications, we try to identify the biological mechanism involved at the cell level through microarray screening. For this study, we use epidermis cultures harvested from human abdominoplasty. Two platinum electrodes are used to apply the electric signal. The gene expressions of 38,500 well-characterized human genes are analyzed using Affymetrix(®) microarray U133 Plus 2.0 chips. The protocol is repeated on three different patients. After three periods of exposure, a total of 24 chips have been processed. After the application of ELF electric fields, the microarray analysis confirms a modification of the gene expression of epidermis cells. Particularly, four up-regulated genes (DKK1, TXNRD1, ATF3, and MME) and one down-regulated gene (MACF1) are involved in the regulation of proliferation and differentiation. Expression of these five genes was also confirmed by real-time rtPCR in all samples used for microarray analysis. These results corroborate an acceleration of cell differentiation at the expense of cell proliferation. © 2010 Wiley-Liss, Inc.

Expression signatures of early-stage and advanced medaka melanomas.

PubMed

Klotz, Barbara; Kneitz, Susanne; Regensburger, Martina; Hahn, Lena; Dannemann, Michael; Kelso, Janet; Nickel, Birgit; Lu, Yuan; Boswell, William; Postlethwait, John; Warren, Wesley; Kunz, Manfred; Walter, Ronald B; Schartl, Manfred

2018-06-01

Melanoma is one of the most aggressive tumors with a very low survival rate once metastasized. The incidence of newly detected cases increases every year suggesting the necessity of development and application of innovative treatment strategies. Human melanoma develops from melanocytes localized in the epidermis of the skin to malignant tumors because of deregulated effectors influencing several molecular pathways. Despite many advances in describing the molecular changes accompanying melanoma formation, many critical and clinically relevant molecular features of the transformed pigment cells and the underlying mechanisms are largely unknown. To contribute to a better understanding of the molecular processes of melanoma formation, we use a transgenic medaka melanoma model that is well suited for the investigation of melanoma tumor development because fish and human melanocytes are both localized in the epidermis. The purpose of our study was to gain insights into melanoma development from the first steps of tumor formation up to melanoma progression and to identify gene expression patterns that will be useful for monitoring treatment effects in drug screening approaches. Comparing transcriptomes from juvenile fish at the tumor initiating stage with nevi and advanced melanoma of adults, we identified stage specific expression signatures and pathways that are characteristic for the development of medaka melanoma, and are also found in human malignancies. Copyright © 2017 Elsevier Inc. All rights reserved.

Cutaneous gene expression of plasmid DNA in excised human skin following delivery via microchannels created by radio frequency ablation.

PubMed

Birchall, James; Coulman, Sion; Anstey, Alexander; Gateley, Chris; Sweetland, Helen; Gershonowitz, Amikam; Neville, Lewis; Levin, Galit

2006-04-07

The skin is a valuable organ for the development and exploitation of gene medicines. Delivering genes to skin is restricted however by the physico-chemical properties of DNA and the stratum corneum (SC) barrier. In this study, we demonstrate the utility of an innovative technology that creates transient microconduits in human skin, allowing DNA delivery and resultant gene expression within the epidermis and dermis layers. The radio frequency (RF)-generated microchannels were of sufficient morphology and depth to permit the epidermal delivery of 100 nm diameter nanoparticles. Model fluorescent nanoparticles were used to confirm the capacity of the channels for augmenting diffusion of macromolecules through the SC. An ex vivo human organ culture model was used to establish the gene expression efficiency of a beta-galactosidase reporter plasmid DNA applied to ViaDerm treated skin. Skin treated with ViaDerm using 50 microm electrode arrays promoted intense levels of gene expression in the viable epidermis. The intensity and extent of gene expression was superior when ViaDerm was used following a prior surface application of the DNA formulation. In conclusion, the RF-microchannel generator (ViaDerm) creates microchannels amenable for delivery of nanoparticles and gene therapy vectors to the viable region of skin.

C-terminal peptides of tissue factor pathway inhibitor are novel host defense molecules.

PubMed

Papareddy, Praveen; Kalle, Martina; Kasetty, Gopinath; Mörgelin, Matthias; Rydengård, Victoria; Albiger, Barbara; Lundqvist, Katarina; Malmsten, Martin; Schmidtchen, Artur

2010-09-03

Tissue factor pathway inhibitor (TFPI) inhibits tissue factor-induced coagulation, but may, via its C terminus, also modulate cell surface, heparin, and lipopolysaccharide interactions as well as participate in growth inhibition. Here we show that C-terminal TFPI peptide sequences are antimicrobial against the gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, gram-positive Bacillus subtilis and Staphylococcus aureus, as well as the fungi Candida albicans and Candida parapsilosis. Fluorescence studies of peptide-treated bacteria, paired with analysis of peptide effects on liposomes, showed that the peptides exerted membrane-breaking effects similar to those seen for the "classic" human antimicrobial peptide LL-37. The killing of E. coli, but not P. aeruginosa, by the C-terminal peptide GGLIKTKRKRKKQRVKIAYEEIFVKNM (GGL27), was enhanced in human plasma and largely abolished in heat-inactivated plasma, a phenomenon linked to generation of antimicrobial C3a and activation of the classic pathway of complement activation. Furthermore, GGL27 displayed anti-endotoxic effects in vitro and in vivo in a mouse model of LPS shock. Importantly, TFPI was found to be expressed in the basal layers of normal epidermis, and was markedly up-regulated in acute skin wounds as well as wound edges of chronic leg ulcers. Furthermore, C-terminal fragments of TFPI were associated with bacteria present in human chronic leg ulcers. These findings suggest a new role for TFPI in cutaneous defense against infections.

Somatostatin receptors are strongly expressed in palmoplantar sweat glands and ducts: studies of normal and palmoplantar pustulosis skin.

PubMed

Hagforsen, E; Michaëlsson, G; Stridsberg, M

2011-07-01

The acrosyringium is the target for inflammation in the chronic and intensely inflammatory skin disease palmoplantar pustulosis (PPP). The sweat-gland apparatus seems to be an immunocompetent structure that probably contributes to skin defence. Furthermore, the sweat gland and duct may be a hitherto unrecognized neuroendocrine organ. To obtain further information about the neuroendocrine properties of the sweat-gland apparatus by examining expression of the somatostatin receptors (SSTRs) 1-5 in healthy palmar skin and in PPP skin. Biopsy specimens were taken from 25 patients with PPP and 25 healthy controls. Immunohistochemical analysis was used to investigate expression of SSTRs 1-5. SSTRs 1-5 were expressed in both epidermal and endothelial structures. The staining intensity of the sweat-gland apparatus was more pronounced than that of the epidermis. Expression differed significantly between lesional PPP and normal plantar skin, with increased expression of SSTRs 3 and 4 in ducts in epidermis, and decreased expression of SSTR 1 in ducts in both papillary and reticular dermis. In specimens with pronounced inflammation, numerous dendritic cells with strong expression of SSTRs 1, 2 and 4 were seen, especially in the papillary dermis. The presence of SSTRs in palmoplantar skin, and specifically at high density in the sweat glands and ducts, might be of particular importance in skin neuroimmunoendocrinology. Although the relevance of the changes in SSTR expression in PPP skin compared with normal skin is unclear, our hypothesis is that these differences might influence the function of both the neuroendocrine and neuroimmunological properties of palmoplantar skin, especially in the sweat-gland apparatus. © The Author(s). CED © 2011 British Association of Dermatologists.

Effects of two water disinfectants (chloramine T and peracetic acid) on the epidermis and gills of Garra rufa used in human ichthyotherapy.

PubMed

Sirri, R; Zaccaroni, A; Di Biase, A; Mordenti, O; Stancampiano, L; Sarli, G; Mandrioli, L

2013-01-01

Doctor fish (Garra rufa) have recently been used for aesthetic purposes and as a medical treatment in patients with psoriasis (ichthyotherapy). For this particular kind of human therapy it is essential to guarantee adequate hygienic conditions for both people and fish. The aim of this study was to test two concentrations of water disinfectants, chloramine T and peracetic acid, on Garra rufa to ascertain possible exposure damage to the epidermis and gills. Fish were exposed to 2 mg/l and 10 mg/l of chloramine T and to 15 microl/l and 45 microl/l of peracetic acid in a 40-minute static bath up to six times a day for one week. The epidermis and gills were checked for histological changes and the number of epidermal mucous cells, club cells and taste buds were quantified; mucous cells were also characterized histochemically to detect alterations in mucin production. No mortality or severe histological changes were found in treated or control fish. Cell count showed a significant increase (p < 0.05) in mucous cells (mean 49.1 +/- 6.7 vs 37.0 +/- 13.1 of controls) in animals treated with peracetic acid independently of the dose. Club cell number showed a significant (p < 0.05) decrease in fish treated with 2 mg/l of chloramine T (mean 74.3 +/- 15.6) and with 45 microl/1 of peracetic acid (mean 78.17 +/- 10.5) compared to controls (mean 107.0 +/- 19.2). Histochemical evaluation of mucous cells did not reveal changes in mucin type in fish exposed to the two disinfectants. The results suggest a good tolerability of Garra rufa to the two disinfectants at the concentrations tested.

The role of topically applied L-ascorbic acid in ex-vivo examination of burn-injured human skin

NASA Astrophysics Data System (ADS)

Pielesz, Anna; Biniaś, Dorota; Bobiński, Rafał; Sarna, Ewa; Paluch, Jadwiga; Waksmańska, Wioletta

2017-10-01

Wound treatment and healing is complex and is comprised of an elaborate set of processes including cellular, spectroscopic and biochemical ones as well as the ;reaction; of local tissue to thermal injury. Vitamin C as L-ascorbic acid (LA) prevents injurious effects of oxidants because it reduces reactive oxygen species to stable molecules, it becomes oxidized to the short-lived ascorbyl radical. As a result, antioxidant treatment may contribute to minimizing injury in burn patients. The aim of this study is to assess changes in molecular structure of collagen extracted from human epidermis burn wound scab during incubation of the epidermis in L-ascorbic acid solution. The study will be performed using FTIR and FT Raman spectroscopies. During this research it was observed that the intensity of Raman peaks increased where healing was being modified by LA. The intensity of the amide III band at 1247 cm- 1 relative to the intensity at 1326 cm- 1 was used to test tissue repair degree at the incision site. FTIR spectra were recorded from frozen specimens of serum modified by LA; an analysis of shifts in the amide I band position was conducted. The appearance of a new band for frozen samples modified by LA was observed around 1149-1220 cm- 1. The above conclusions confirmed the creation of hydrogen bonds between Nsbnd H stretch and Cdbnd O. Samples being incubated in solutions of L-ascorbic acid demonstrated the absence of electrophoretic bands of albumin. Alterations in the surface of the skin incubated in L-ascorbic acid were investigated with the use of Scanning Electron Microscopy (SEM). A decrease in external symptoms of burn injury was noted in the damaged epidermis incubated in L-ascorbic acid.

Lower levels of interleukin-1β gene expression are associated with impaired Langerhans' cell migration in aged human skin.

PubMed

Pilkington, Suzanne M; Ogden, Stephanie; Eaton, Laura H; Dearman, Rebecca J; Kimber, Ian; Griffiths, Christopher E M

2018-01-01

Langerhans' cells (LC) play pivotal roles in skin immune responses, linking innate and adaptive immunity. In aged skin there are fewer LC and migration is impaired compared with young skin. These changes may contribute to declining skin immunity in the elderly, including increased skin infections and skin cancer. Interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α) are mandatory signals for LC migration and previous studies suggest that IL-1β signalling may be dysregulated in aged skin. Therefore, we sought to explore the mechanisms underlying these phenomena. In skin biopsies of photoprotected young (< 30 years) and aged (> 70 years) human skin ex vivo, we assessed the impact of trauma, and mandatory LC mobilizing signals on LC migration and gene expression. Biopsy-related trauma induced LC migration from young epidermis, whereas in aged skin, migration was greatly reduced. Interleukin-1β treatment restored LC migration in aged epidermis whereas TNF-α was without effect. In uncultured, aged skin IL-1β gene expression was lower compared with young skin; following culture, IL-1βmRNA remained lower in aged skin under control and TNF-α conditions but was elevated after culture with IL-1β. Interleukin-1 receptor type 2 (IL1R2) gene expression was significantly increased in aged, but not young skin, after cytokine treatment. Keratinocyte-derived factors secreted from young and aged primary cells did not restore or inhibit LC migration from aged and young epidermis, respectively. These data suggest that in aged skin, IL-1β signalling is diminished due to altered expression of IL1B and decoy receptor gene IL1R2. © 2017 The Authors. Immunology Published by John Wiley & Sons Ltd., Immunology.

Inhibitory mechanism of an extract of Althaea officinalis L. on endothelin-1-induced melanocyte activation.

PubMed

Kobayashi, Akemi; Hachiya, Akira; Ohuchi, Atsushi; Kitahara, Takashi; Takema, Yoshinori

2002-02-01

It is known that expression of endothelin-1 (ET-1) increases in the epidermis after UVB irradiation, and that this plays an important role during the induction of pigmentation both as a mitogen and as a melanogen for normal human melanocytes (NHMC). When ET-1 acts on NHMC via the endothelin B receptor (ET(B)R) on their cell surface, mobilization of intracellular calcium is induced, which is followed by activation of Raf-1 located upstream of mitogen activated protein kinase (MAPK). We have continued the search for new agent which inhibit this calcium mobilization and we have found that an extract of Althaea officinalis L. has such an action. In this study, we investigated the precise inhibitory mechanism of this botanical extract on the ET-1-induced activation of melanocytes. Treatment of NHMC with this extract abrogated the stimulatory effect of ET-1 on proliferation and also on activation of MAPK in the intracellular signal transduction pathway, but did not affect the binding of ET-1 to the ET(B)R or the production of Inositol 1,4,5-Trisphosphate (IP3). Further, when this extract was used to treat normal human keratinocytes (NHKC), secretion of ET-1 by those cells was reduced. Taken together, these findings indicate that an extract of A. officinalis inhibits both the secretion of ET-1 from NHKC and the action of ET-1 on NHMC mainly by suppressing the ET-1-induced calcium mobilization without the modification of IP3 production, which in turn suggests that this extract is a useful ingredient for a whitening agent.

Two patterns of solar lentigines: a histopathological analysis of 40 Japanese women.

PubMed

Yonei, Nozomi; Kaminaka, Chikako; Kimura, Ayako; Furukawa, Fukumi; Yamamoto, Yuki

2012-10-01

Solar lentigines are common acquired pigmented lesions on sun-exposed skin. Their histopathological features have been reported as large numbers of melanocytes at the base of clubbed and budding rete ridges. In this study, biopsies were taken from facial solar lentigines in 40 Japanese women, and the sections were stained using hematoxylin-eosin, Fontana-Masson, and immunostained for melanocytes and Langerhans cells in order to verify the histological patterns of Japanese patients. We characterized the histopathological features of solar lentigines on the face and identified two patterns: one pattern (20/40 cases) demonstrated a flattened epidermis with basal melanosis, and the other pattern (20/40 cases) showed epidermal hyperplasia with elongated rete ridges composed of deeply pigmented basaloid cells. We termed the former pattern the "flattened epidermis" group, and the latter the "budding" group, respectively. The flattened epidermis group showed a significantly thinner epidermis, more severe solar elastosis and fewer Langerhans cells in the epidermis as compared with the budding group. We concluded that more severely sun-damaged solar lentigines might show the changes observed in the flattened epidermis group. Langerhans cells in the epidermis of solar lentigines might play a role in the remission of postinflammatory pigmentation due to aesthetic treatment. © 2012 Japanese Dermatological Association.

Identification of a Novel Proto-oncogenic Network in Head and Neck Squamous Cell Carcinoma

PubMed Central

Georgy, Smitha R.; Cangkrama, Michael; Srivastava, Seema; Partridge, Darren; Auden, Alana; Dworkin, Sebastian; McLean, Catriona A.; Darido, Charbel

2015-01-01

Background: The developmental transcription factor Grainyhead-like 3 (GRHL3) plays a critical tumor suppressor role in the mammalian epidermis through direct regulation of PTEN and the PI3K/AKT/mTOR signaling pathway. GRHL3 is highly expressed in all tissues derived from the surface ectoderm, including the oral cavity, raising a question about its potential role in suppression of head and neck squamous cell carcinoma (HNSCC). Methods: We explored the tumor suppressor role of Grhl3 in HNSCC using a conditional knockout (Grhl3 ∆/– /K14Cre +) mouse line (n = 26) exposed to an oral chemical carcinogen. We defined the proto-oncogenic pathway activated in the HNSCC derived from these mice and assessed it in primary human HNSCC samples, normal oral epithelial cell lines carrying shRNA to GRHL3, and human HNSCC cell lines. Data were analyzed with two-sided chi square and Student’s t tests. Results: Deletion of Grhl3 in oral epithelium in mice did not perturb PTEN/PI3K/AKT/mTOR signaling, but instead evoked loss of GSK3B expression, resulting in stabilization and accumulation of c-MYC and aggressive HNSCC. This molecular signature was also evident in a subset of primary human HNSCC and HNSCC cell lines. Loss of Gsk3b in mice, independent of Grhl3, predisposed to chemical-induced HNSCC. Restoration of GSK3B expression blocked proliferation of normal oral epithelial cell lines carrying shRNA to GRHL3 (cell no., Day 8: Scramble ctl, 616±21.8 x 103 vs GRHL3-kd, 1194±44 X 103, P < .001; GRHL3-kd vs GRHL3-kd + GSK3B, 800±98.84 X 103, P = .003) and human HNSCC cells. Conclusions: We defined a novel molecular signature in mammalian HNSCC, suggesting new treatment strategies targeting the GRHL3/GSK3B/c-MYC proto-oncogenic network. PMID:26063791

Grover Disease With Epidermal Dysmaturation Pattern: a Common Histopathologic Finding.

PubMed

Aljarbou, Ohoud Z; Asgari, Masoud; Al-Saidi, Nagla; Silloca-Cabana, Elizabeth O; Alathamneh, Mamoun; Sangueza, Omar

2018-02-06

Grover disease is an entity whose diagnosis is based on clinicopathologic correlation. Histopathologically, focal acantholysis is the most common finding. In some cases, there is prominent squamous atypia which can prove to be very challenging and the lesion may be confused with an epidermal neoplasm. To report on atypical histopathological changes in Grover disease and to provide helpful clues to differentiate between the epidermal atypia seen in some cases of Grover disease and epithelial neoplasms. We analyzed 33 cases of Grover disease histologically diagnosed at Wake Forest Baptist Medical Center, NC, between 2011 and 2017. Atypical changes in keratinocytes were defined as epithelial buds, nuclear pleomorphism, and dyskeratosis in all layers of epidermis or altered granular layer. Twenty cases (64%) showed foci with alteration of the normal keratinocytic maturation, whereas 18 cases demonstrated nuclear pleomorphism. Buds of epithelial cells emanating from the basal layer of the epidermis and granular cell alteration was present in 19 cases. The findings especially the presence of an altered granular layer may represent a diagnostic clue in cases of Grover disease with atypical changes.

Preparation of A Spaceflight: Apoptosis Search in Sutured Wound Healing Models.

PubMed

Riwaldt, Stefan; Monici, Monica; Graver Petersen, Asbjørn; Birk Jensen, Uffe; Evert, Katja; Pantalone, Desiré; Utpatel, Kirsten; Evert, Matthias; Wehland, Markus; Krüger, Marcus; Kopp, Sascha; Frandsen, Sofie; Corydon, Thomas; Sahana, Jayashree; Bauer, Johann; Lützenberg, Ronald; Infanger, Manfred; Grimm, Daniela

2017-12-03

To prepare the ESA (European Space Agency) spaceflight project "Wound healing and Sutures in Unloading Conditions", we studied mechanisms of apoptosis in wound healing models based on ex vivo skin tissue cultures, kept for 10 days alive in serum-free DMEM/F12 medium supplemented with bovine serum albumin, hydrocortisone, insulin, ascorbic acid and antibiotics at 32 °C. The overall goal is to test: (i) the viability of tissue specimens; (ii) the gene expression of activators and inhibitors of apoptosis and extracellular matrix components in wound and suture models; and (iii) to design analytical protocols for future tissue specimens after post-spaceflight download. Hematoxylin-Eosin and Elastica-van-Gieson staining showed a normal skin histology with no signs of necrosis in controls and showed a normal wound suture. TdT-mediated dUTP-biotin nick end labeling for detecting DNA fragmentation revealed no significant apoptosis. No activation of caspase-3 protein was detectable. FASL , FADD , CASP3 , CASP8 , CASP10 , BAX , BCL2 , CYC1 , APAF1 , LAMA3 and SPP1 mRNAs were not altered in epidermis and dermis samples with and without a wound compared to 0 day samples (specimens investigated directly post-surgery). BIRC5 , CASP9 , and FN1 mRNAs were downregulated in epidermis/dermis samples with and/or without a wound compared to 0 day samples. BIRC2 , BIRC3 were upregulated in 10 day wound samples compared to 0 day samples in epidermis/dermis. RELA/FAS mRNAs were elevated in 10 day wound and no wound samples compared to 0 day samples in dermis. In conclusion, we demonstrate that it is possible to maintain live skin tissue cultures for 10 days. The viability analysis showed no significant signs of cell death in wound and suture models. The gene expression analysis demonstrated the interplay of activators and inhibitors of apoptosis and extracellular matrix components, thereby describing important features in ex vivo sutured wound healing models. Collectively, the performed methods defining analytical protocols proved to be applicable for post-flight analyzes of tissue specimens after sample return.

ACR4, a putative receptor kinase gene of Arabidopsis thaliana, that is expressed in the outer cell layers of embryos and plants, is involved in proper embryogenesis.

PubMed

Tanaka, Hirokazu; Watanabe, Masaru; Watanabe, Daisuke; Tanaka, Toshihiro; Machida, Chiyoko; Machida, Yasunori

2002-04-01

The surfaces of higher plants are characterized by epidermis, which usually consists of a single layer of cells. The epidermis is derived from the outer cell layer of the embryo or protoderm, which arises as a result of periclinal cell division. After seed germination, most of the epidermal cells of the aerial parts of plants are derived from the outer cell layer of the shoot apical meristem (the L1 layer). Thus, knowledge of how the protoderm and/or L1 layer is established is fundamental to understanding the morphogenesis of higher plants. Here, we report the isolation of a gene encoding an Arabidopsis homologue (ACR4) of the maize putative receptor kinase CRINKLY4 (CR4), which is involved in epidermal differentiation. The domain organization of the predicted amino acid sequence of ACR4 is essentially identical to that of CR4. ACR4-GFP fusion protein localized to the cell surface when expressed in tobacco cell (BY-2) culture. ACR4 transcripts were detected in all the organs of the Arabidopsis plant. In developing embryos and shoot apices, ACR4 transcripts accumulated in protoderm and epidermis at relatively higher levels than in the inner tissues. Over-expression of antisense ACR4 in Arabidopsis plants resulted in malformation of embryos to varying degrees. These results suggest that ACR4 is, at a minimum, involved in the normal morphogenesis of embryos, most likely through properly differentiating protoderm cells.

Neutrophil extracellular trap formation is increased in psoriasis and induces human β-defensin-2 production in epidermal keratinocytes

PubMed Central

Hu, Stephen Chu-Sung; Yu, Hsin-Su; Yen, Feng-Lin; Lin, Chi-Ling; Chen, Gwo-Shing; Lan, Cheng-Che E.

2016-01-01

Neutrophil extracellular traps (NETs) have been implicated in the development of certain immune-mediated diseases, but their role in psoriasis has not been clearly defined. Human β-defensin-2 (HBD-2) is an important antimicrobial peptide overexpressed in psoriasis epidermis. We evaluated whether the amount of NETs is increased in psoriasis and determined the effect of NETs on HBD-2 production in epidermal keratinocytes. Using fluorescent microscopy, we found that patients with psoriasis (n = 48) had higher amount of NETotic cells in their peripheral blood compared to healthy controls (n = 48) and patients with eczema (n = 35). Psoriasis sera showed increased ability to induce NET formation in control neutrophils but normal NET degradation ability. The amount of NETs in the peripheral blood correlated with psoriasis disease severity. NETosis was also observed in the majority (18 of 20) of psoriasis skin specimens. Furthermore, NETs induced HBD-2 mRNA and protein production in keratinocytes, and immunohistochemical analysis confirmed strong expression of HBD-2 in psoriasis lesional skin. In summary, NET formation is increased in peripheral blood and lesional skin of psoriasis patients and correlates with disease severity. Additionally, NET-induced HBD-2 production may provide a novel mechanism for the decreased susceptibility of psoriasis plaques to microbial infections. PMID:27493143

Asymmetric stem-cell divisions define the architecture of human oesophageal epithelium.

PubMed

Seery, J P; Watt, F M

2000-11-16

In spite of its clinical importance, little is known about the stem-cell compartment of the human oesophageal epithelium [1,2]. The epithelial basal layer consists of two distinct zones, one overlying the papillae of the supporting connective tissue (PBL) and the other covering the interpapillary zone (IBL) [3]. In examining the oesophageal basal layer, we found that proliferating cells were rare in the IBL and a high proportion of mitoses were asymmetrical, giving rise to one basal daughter and one suprabasal, differentiating daughter. In the PBL, mitoses were more frequent and predominantly symmetrical. The IBL was characterised by low expression of ?1 integrins and high expression of the beta2 laminin chain. By combining fluorescence-activated cell sorting (FACS) with in vitro clonal analysis, we obtained evidence that the IBL is enriched for stem cells. A normal oesophageal epithelium with asymmetric divisions was reconstituted on denuded oesophageal connective tissue. In contrast, asymmetric divisions were not sustained on skin connective tissue, and the epithelium formed resembled epidermis. We propose that stem cells located in the IBL give rise to differentiating daughters through asymmetric divisions in response to cues from the underlying basement membrane. Until now, stem-cell fate in stratified squamous epithelia was believed to be achieved largely through populational asymmetry [4-6].

Radiation-Induce Immune Modulation in Prostate Cancer

DTIC Science & Technology

2005-01-01

Prostate-specific antigen Prostate carcinoma Mammoglobin-A Breast carcinoma Overexpressed Alpha - fetoprotein Hepatocellular carcinoma and yolk-sac tumors...Interleukin-3 cooperates with tumor necrosis factor alpha for the development of human dendritic/Langerhans cells from cord blood CD34+ hematopoietic progenitor...additional subsets, e.g. Langerhans cells of the epidermis, and dermal or interstitial DC. PDC are the major interferon- alpha (IFNca) producing cells

Identification of a novel PPARβ/δ/miR-21-3p axis in UV-induced skin inflammation.

PubMed

Degueurce, Gwendoline; D'Errico, Ilenia; Pich, Christine; Ibberson, Mark; Schütz, Frédéric; Montagner, Alexandra; Sgandurra, Marie; Mury, Lionel; Jafari, Paris; Boda, Akash; Meunier, Julien; Rezzonico, Roger; Brembilla, Nicolò Costantino; Hohl, Daniel; Kolios, Antonios; Hofbauer, Günther; Xenarios, Ioannis; Michalik, Liliane

2016-08-01

Although excessive exposure to UV is widely recognized as a major factor leading to skin perturbations and cancer, the complex mechanisms underlying inflammatory skin disorders resulting from UV exposure remain incompletely characterized. The nuclear hormone receptor PPARβ/δ is known to control mouse cutaneous repair and UV-induced skin cancer development. Here, we describe a novel PPARβ/δ-dependent molecular cascade involving TGFβ1 and miR-21-3p, which is activated in the epidermis in response to UV exposure. We establish that the passenger miRNA miR-21-3p, that we identify as a novel UV-induced miRNA in the epidermis, plays a pro-inflammatory function in keratinocytes and that its high level of expression in human skin is associated with psoriasis and squamous cell carcinomas. Finally, we provide evidence that inhibition of miR-21-3p reduces UV-induced cutaneous inflammation in ex vivo human skin biopsies, thereby underlining the clinical relevance of miRNA-based topical therapies for cutaneous disorders. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

Residual antimicrobial effect of chlorhexidine digluconate and octenidine dihydrochloride on reconstructed human epidermis.

PubMed

Müller, G; Langer, J; Siebert, J; Kramer, A

2014-01-01

The objective of the present investigation was to examine the residual antimicrobial activity after a topical exposure of reconstructed human epidermis (RHE) to equimolar solutions of either chlorhexidine digluconate (CHG, 0.144% w/v) or octenidine dihydrochloride (OCT, 0.1% w/v) for 15 min. RHE-associated antiseptic agents were more effective on Staphylococcus aureus than on Pseudomonas aeruginosa. S. aureus was not detected after 24 h of contact, which demonstrated a microbicidal efficacy of greater than 5-log10 reduction. In contrast, P. aeruginosa was reduced by approximately 2 log10 at the same incubation time, which parallels the growth of the initial inoculum. This result could be interpreted either as a microbiostatic effect or as an adherence of P. aeruginosa to a low positively charged surface. Small amounts of CHG and OCT can penetrate the stratum corneum. Using these antiseptic agents, the viability of keratinocytes was reduced to 65-75% of that of the untreated RHE control following 24 h incubation in the presence of test microorganisms. With consideration of antimicrobial activity and cytotoxic effect, OCT corresponds better to a biocompatible antiseptic agent than CHG. Copyright © 2013 S. Karger AG, Basel.

UV-B radiation induces macrophage migration inhibitory factor-mediated melanogenesis through activation of protease-activated receptor-2 and stem cell factor in keratinocytes.

PubMed

Enomoto, Akiko; Yoshihisa, Yoko; Yamakoshi, Takako; Ur Rehman, Mati; Norisugi, Osamu; Hara, Hiroshi; Matsunaga, Kenji; Makino, Teruhiko; Nishihira, Jun; Shimizu, Tadamichi

2011-02-01

UV radiation indirectly regulates melanogenesis in melanocytes through a paracrine regulatory mechanism involving keratinocytes. Protease-activated receptor (PAR)-2 activation induces melanosome transfer by increasing phagocytosis of melanosomes by keratinocytes. This study demonstrated that macrophage migration inhibitory factor (MIF) stimulated PAR-2 expression in human keratinocytes. In addition, we showed that MIF stimulated stem cell factor (SCF) release in keratinocytes; however, MIF had no effect on the release of endothelin-1 or prostaglandin E2 in keratinocytes. In addition, MIF had no direct effect on melanin and tyrosinase synthesis in cultured human melanocytes. The effect of MIF on melanogenesis was also examined using a three-dimensional reconstituted human epidermal culture model, which is a novel, commercially available, cultured human epidermis containing functional melanocytes. Migration inhibitory factor induced an increase in melanin content in the epidermis after a 9-day culture period. Moreover, melanin synthesis induced by UV-B stimulation was significantly down-regulated by anti-MIF antibody treatment. An in vivo study showed that the back skin of MIF transgenic mice had a higher melanin content than that of wild-type mice after 12 weeks of UV-B exposure. Therefore, MIF-mediated melanogenesis occurs mainly through the activation of PAR-2 and SCF expression in keratinocytes after exposure to UV-B radiation. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

SkinEthic Laboratories, a company devoted to develop and produce in vitro alternative methods to animal use.

PubMed

de Brugerolle, Anne

2007-01-01

SkinEthic Laboratories is a France-based biotechnology company recognised as the world leader in tissue engineering. SkinEthic is devoted to develop and produce reliable and robust in vitro alternative methods to animal use in cosmetic, chemical and pharmaceutical industries. SkinEthic models provide relevant tools for efficacy and safety screening tests in order to support an integrated decision-making during research and development phases. Some screening tests are referenced and validated as alternatives to animal use (Episkin), others are in the process of validation under ECVAM and OECD guidelines. SkinEthic laboratories provide a unique and joined experience of more than 20 years from Episkin SNC and SkinEthic SA. Their unique cell culture process allows in vitro reconstructed human tissues with well characterized histology, functionality and ultrastructure features to be mass produced. Our product line includes skin models: a reconstructed human epidermis with a collagen layer, Episkin, reconstructed human epidermis without or with melanocytes (with a tanning degree from phototype II to VI) and a reconstructed human epithelium, i.e. cornea, and other mucosa, i.e. oral, gingival, oesophageal and vaginal. Our philosophy is based on 3 main commitments: to support our customers by providing robust and reliable models, to ensure training and education in using validated protocols, allowing a large array of raw materials, active ingredients and finished products in solid, liquid, powder, cream or gel form to be screened, and, to provide a dedicated service to our partners.

Design and Fabrication of Human Skin by Three-Dimensional Bioprinting

PubMed Central

Lee, Vivian; Singh, Gurtej; Trasatti, John P.; Bjornsson, Chris; Xu, Xiawei; Tran, Thanh Nga; Yoo, Seung-Schik

2014-01-01

Three-dimensional (3D) bioprinting, a flexible automated on-demand platform for the free-form fabrication of complex living architectures, is a novel approach for the design and engineering of human organs and tissues. Here, we demonstrate the potential of 3D bioprinting for tissue engineering using human skin as a prototypical example. Keratinocytes and fibroblasts were used as constituent cells to represent the epidermis and dermis, and collagen was used to represent the dermal matrix of the skin. Preliminary studies were conducted to optimize printing parameters for maximum cell viability as well as for the optimization of cell densities in the epidermis and dermis to mimic physiologically relevant attributes of human skin. Printed 3D constructs were cultured in submerged media conditions followed by exposure of the epidermal layer to the air–liquid interface to promote maturation and stratification. Histology and immunofluorescence characterization demonstrated that 3D printed skin tissue was morphologically and biologically representative of in vivo human skin tissue. In comparison with traditional methods for skin engineering, 3D bioprinting offers several advantages in terms of shape- and form retention, flexibility, reproducibility, and high culture throughput. It has a broad range of applications in transdermal and topical formulation discovery, dermal toxicity studies, and in designing autologous grafts for wound healing. The proof-of-concept studies presented here can be further extended for enhancing the complexity of the skin model via the incorporation of secondary and adnexal structures or the inclusion of diseased cells to serve as a model for studying the pathophysiology of skin diseases. PMID:24188635

Design and fabrication of human skin by three-dimensional bioprinting.

PubMed

Lee, Vivian; Singh, Gurtej; Trasatti, John P; Bjornsson, Chris; Xu, Xiawei; Tran, Thanh Nga; Yoo, Seung-Schik; Dai, Guohao; Karande, Pankaj

2014-06-01

Three-dimensional (3D) bioprinting, a flexible automated on-demand platform for the free-form fabrication of complex living architectures, is a novel approach for the design and engineering of human organs and tissues. Here, we demonstrate the potential of 3D bioprinting for tissue engineering using human skin as a prototypical example. Keratinocytes and fibroblasts were used as constituent cells to represent the epidermis and dermis, and collagen was used to represent the dermal matrix of the skin. Preliminary studies were conducted to optimize printing parameters for maximum cell viability as well as for the optimization of cell densities in the epidermis and dermis to mimic physiologically relevant attributes of human skin. Printed 3D constructs were cultured in submerged media conditions followed by exposure of the epidermal layer to the air-liquid interface to promote maturation and stratification. Histology and immunofluorescence characterization demonstrated that 3D printed skin tissue was morphologically and biologically representative of in vivo human skin tissue. In comparison with traditional methods for skin engineering, 3D bioprinting offers several advantages in terms of shape- and form retention, flexibility, reproducibility, and high culture throughput. It has a broad range of applications in transdermal and topical formulation discovery, dermal toxicity studies, and in designing autologous grafts for wound healing. The proof-of-concept studies presented here can be further extended for enhancing the complexity of the skin model via the incorporation of secondary and adnexal structures or the inclusion of diseased cells to serve as a model for studying the pathophysiology of skin diseases.

The effects of 595- and 1,064-nm lasers on rooster comb blood vessels using dual-wavelength and multipulse techniques.

PubMed

Li, Guang; Sun, Jianfang; Shao, Xuebao; Sang, Honggui; Zhou, Zhanchao

2011-10-01

After laser irradiation, hemoglobin can transform into methemoglobin and coagulum, which have high absorptivity of near-infrared light. Sequential irradiation with 595 nm and 1,064 nm may be more effective than single wavelength to decrease residual vessel number in rooster combs. Six protocols (single pulse with 595 nm, double pulse with 595 nm, single pulse with 1,064 nm, double pulse with 1,064 nm, sequential irradiation with 595 nm and 1,064 nm (multiplex), and a blank control group) were used to compare the effects of sequential and single-wavelength irradiation on reducing residual vessel number, as well as the epidermal side effects, in the rooster comb. Different treatment techniques were applied to the same comb, at the same time. The treated areas of the epidermis and the residual vessels were observed using an optical microscope. All five techniques were effective in decreasing the number of residual vessels in the comb, and the side effects on the epidermis were similar for all. Considering the selectivity of the 595-nm laser and the rich melanin in the human epidermis, the dual-wavelength laser has a distinct advantage in treating vascular lesions. The authors have indicated no significant interest with commercial supporters. © 2011 by the American Society for Dermatologic Surgery, Inc.

Catch-up validation study of an in vitro skin irritation test method based on an open source reconstructed epidermis (phase II).

PubMed

Groeber, F; Schober, L; Schmid, F F; Traube, A; Kolbus-Hernandez, S; Daton, K; Hoffmann, S; Petersohn, D; Schäfer-Korting, M; Walles, H; Mewes, K R

2016-10-01

To replace the Draize skin irritation assay (OECD guideline 404) several test methods based on reconstructed human epidermis (RHE) have been developed and were adopted in the OECD test guideline 439. However, all validated test methods in the guideline are linked to RHE provided by only three companies. Thus, the availability of these test models is dependent on the commercial interest of the producer. To overcome this limitation and thus to increase the accessibility of in vitro skin irritation testing, an open source reconstructed epidermis (OS-REp) was introduced. To demonstrate the capacity of the OS-REp in regulatory risk assessment, a catch-up validation study was performed. The participating laboratories used in-house generated OS-REp to assess the set of 20 reference substances according to the performance standards amending the OECD test guideline 439. Testing was performed under blinded conditions. The within-laboratory reproducibility of 87% and the inter-laboratory reproducibility of 85% prove a high reliability of irritancy testing using the OS-REp protocol. In addition, the prediction capacity was with an accuracy of 80% comparable to previous published RHE based test protocols. Taken together the results indicate that the OS-REp test method can be used as a standalone alternative skin irritation test replacing the OECD test guideline 404. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Gelatin for purification and proliferation of primary keratinocyte culture for use in chronic wounds and burns.

PubMed

Rahsaz, Marjan; Geramizadeh, Bita; Kaviani, Maryam; Marzban, Saeed

2015-04-01

Human epidermal keratinocytes are currently established as a treatment for burns and wounds and have laboratory applications. Keratinocyte culture contamination by unwanted cells and inhibition of cell proliferation are barriers in primary keratinocyte culture. According to the recent literature, these cells are hard to culture. The present study was conducted to evaluate the efficacy of gelatin-coated surfaces in keratinocyte cultures. After enzymatic isolation of keratinocytes from normal epidermis by trypsin, the cells were cultured on gelatin-coated flasks in serum-free medium. Another group of cells were cultured as a control group without gelatin coating. We showed positive effects of surface coating with gelatin on the primary culture of keratinocytes. Culture of these cells on a gelatincoated surface showed better proliferation with suitable morphology. By using gelatin, adhesion of these cells to the surface was more efficient and without contamination by small round cells. Successful primary culture of keratinocytes on a gelatin-coated surface may provide better yield and optimal number of cells for research and clinical applications.

Heterogeneous fates and dynamic rearrangement of regenerative epidermis-derived cells during zebrafish fin regeneration.

PubMed

Shibata, Eri; Ando, Kazunori; Murase, Emiko; Kawakami, Atsushi

2018-04-13

The regenerative epidermis (RE) is a specialized tissue that plays an essential role in tissue regeneration. However, the fate of the RE during and after regeneration is unknown. In this study, we performed Cre- loxP -mediated cell fate tracking and revealed the fates of a major population of the RE cells that express fibronectin 1b ( fn1b ) during zebrafish fin regeneration. Our study showed that these RE cells are mainly recruited from the inter-ray epidermis, and that they follow heterogeneous cell fates. Early recruited cells contribute to initial wound healing and soon disappear by apoptosis, while the later recruited cells contribute to the regenerated epidermis. Intriguingly, many of these cells are also expelled from the regenerated tissue by a dynamic caudal movement of the epidermis over time, and in turn the loss of epidermal cells is replenished by a global self-replication of basal and suprabasal cells in fin. De-differentiation of non-basal epidermal cells into the basal epidermal cells did not occur during regeneration. Overall, our study reveals the heterogeneous fates of RE cells and a dynamic rearrangement of the epidermis during and after regeneration. © 2018. Published by The Company of Biologists Ltd.

Collagen XII and XIV, new partners of cartilage oligomeric matrix protein in the skin extracellular matrix suprastructure.

PubMed

Agarwal, Pallavi; Zwolanek, Daniela; Keene, Douglas R; Schulz, Jan-Niklas; Blumbach, Katrin; Heinegård, Dick; Zaucke, Frank; Paulsson, Mats; Krieg, Thomas; Koch, Manuel; Eckes, Beate

2012-06-29

The tensile and scaffolding properties of skin rely on the complex extracellular matrix (ECM) that surrounds cells, vasculature, nerves, and adnexus structures and supports the epidermis. In the skin, collagen I fibrils are the major structural component of the dermal ECM, decorated by proteoglycans and by fibril-associated collagens with interrupted triple helices such as collagens XII and XIV. Here we show that the cartilage oligomeric matrix protein (COMP), an abundant component of cartilage ECM, is expressed in healthy human skin. COMP expression is detected in the dermal compartment of skin and in cultured fibroblasts, whereas epidermis and HaCaT cells are negative. In addition to binding collagen I, COMP binds to collagens XII and XIV via their C-terminal collagenous domains. All three proteins codistribute in a characteristic narrow zone in the superficial papillary dermis of healthy human skin. Ultrastructural analysis by immunogold labeling confirmed colocalization and further revealed the presence of COMP along with collagens XII and XIV in anchoring plaques. On the basis of these observations, we postulate that COMP functions as an adapter protein in human skin, similar to its function in cartilage ECM, by organizing collagen I fibrils into a suprastructure, mainly in the vicinity of anchoring plaques that stabilize the cohesion between the upper dermis and the basement membrane zone.

Collagen XII and XIV, New Partners of Cartilage Oligomeric Matrix Protein in the Skin Extracellular Matrix Suprastructure*

PubMed Central

Agarwal, Pallavi; Zwolanek, Daniela; Keene, Douglas R.; Schulz, Jan-Niklas; Blumbach, Katrin; Heinegård, Dick; Zaucke, Frank; Paulsson, Mats; Krieg, Thomas; Koch, Manuel; Eckes, Beate

2012-01-01

The tensile and scaffolding properties of skin rely on the complex extracellular matrix (ECM) that surrounds cells, vasculature, nerves, and adnexus structures and supports the epidermis. In the skin, collagen I fibrils are the major structural component of the dermal ECM, decorated by proteoglycans and by fibril-associated collagens with interrupted triple helices such as collagens XII and XIV. Here we show that the cartilage oligomeric matrix protein (COMP), an abundant component of cartilage ECM, is expressed in healthy human skin. COMP expression is detected in the dermal compartment of skin and in cultured fibroblasts, whereas epidermis and HaCaT cells are negative. In addition to binding collagen I, COMP binds to collagens XII and XIV via their C-terminal collagenous domains. All three proteins codistribute in a characteristic narrow zone in the superficial papillary dermis of healthy human skin. Ultrastructural analysis by immunogold labeling confirmed colocalization and further revealed the presence of COMP along with collagens XII and XIV in anchoring plaques. On the basis of these observations, we postulate that COMP functions as an adapter protein in human skin, similar to its function in cartilage ECM, by organizing collagen I fibrils into a suprastructure, mainly in the vicinity of anchoring plaques that stabilize the cohesion between the upper dermis and the basement membrane zone. PMID:22573329

miR-203 modulates epithelial differentiation of human embryonic stem cells towards epidermal stratification.

PubMed

Nissan, Xavier; Denis, Jérôme Alexandre; Saidani, Manoubia; Lemaitre, Gilles; Peschanski, Marc; Baldeschi, Christine

2011-08-15

The molecular mechanisms controlling the differentiation of human basal keratinocyte stem cells towards the epidermis are well characterized, whereas the earliest process leading to the specification of embryonic stem cells into keratinocytes is still not well understood. MicroRNAs are regulators of many cellular events, but evidence for microRNA acting on the differentiation of human embryonic stem cells into a specific lineage has been elusive. By using our recent protocol for obtaining functional keratinocytes from hESC, we attempted to analyze the role of microRNAs in the early stages of epidermal differentiation. Thus, we identified a set of 5 microRNAs, namely miR-200a, miR-200b, miR-203, miR-205 and miR-429, that are specifically overexpressed during the early stages of the differentiation process. Interestingly, our functional analyses revealed an instrumental role of miR-203, which had been previously shown to play a key role during the formation of the pluristratified epidermis by basal keratinocyte stem cells, in the early keratinocyte commitment. These results highlight the determinant and unique role of miR-203 during the entire process of epidermal development by extending its spectrum of action from the early commitment of embryonic stem cells to ultimate differentiation of the organ. Copyright © 2011 Elsevier Inc. All rights reserved.

Enhanced skin permeation of naltrexone by pulsed electromagnetic fields in human skin in vitro.

PubMed

Krishnan, Gayathri; Edwards, Jeffrey; Chen, Yan; Benson, Heather A E

2010-06-01

The aim of the present study was to evaluate the skin permeation of naltrexone (NTX) under the influence of a pulsed electromagnetic field (PEMF). The permeation of NTX across human epidermis and a silicone membrane in vitro was monitored during and after application of the PEMF and compared to passive application. Enhancement ratios of NTX human epidermis permeation by PEMF over passive diffusion, calculated based on the AUC of cumulative NTX permeation to the receptor compartment verses time for 0-4 h, 4-8 h, and over the entire experiment (0-8 h) were 6.52, 5.25, and 5.66, respectively. Observation of the curve indicated an initial enhancement of NTX permeation compared to passive delivery whilst the PEMF was active (0-4 h). This was followed by a secondary phase after termination of PEMF energy (4-8 h) in which there was a steady increase in NTX permeation. No significant enhancement of NTX penetration across silicone membrane occurred with PEMF application in comparison to passively applied NTX. In a preliminary experiment PEMF enhanced the penetration of 10 nm gold nanoparticles through the stratum corneum as visualized by multiphoton microscopy. This suggests that the channels through which the nanoparticles move must be larger than the 10 nm diameter of these rigid particles. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association

Measurements of the thermal coefficient of optical attenuation at different depth regions of in vivo human skins using optical coherence tomography: a pilot study

PubMed Central

Su, Ya; Yao, X. Steve; Li, Zhihong; Meng, Zhuo; Liu, Tiegen; Wang, Longzhi

2015-01-01

We present detailed measurement results of optical attenuation’s thermal coefficients (referenced to the temperature of the skin surface) in different depth regions of in vivo human forearm skins using optical coherence tomography (OCT). We first design a temperature control module with an integrated optical probe to precisely control the surface temperature of a section of human skin. We propose a method of using the correlation map to identify regions in the skin having strong correlations with the surface temperature of the skin and find that the attenuation coefficient in these regions closely follows the variation of the surface temperature without any hysteresis. We observe a negative thermal coefficient of attenuation in the epidermis. While in dermis, the slope signs of the thermal coefficient of attenuation are different at different depth regions for a particular subject, however, the depth regions with a positive (or negative) slope are different in different subjects. We further find that the magnitude of the thermal coefficient of attenuation coefficient is greater in epidermis than in dermis. We believe the knowledge of such thermal properties of skins is important for several noninvasive diagnostic applications, such as OCT glucose monitoring, and the method demonstrated in this paper is effective in studying the optical and biological properties in different regions of skin. PMID:25780740

Standardized 3D Bioprinting of Soft Tissue Models with Human Primary Cells.

PubMed

Rimann, Markus; Bono, Epifania; Annaheim, Helene; Bleisch, Matthias; Graf-Hausner, Ursula

2016-08-01

Cells grown in 3D are more physiologically relevant than cells cultured in 2D. To use 3D models in substance testing and regenerative medicine, reproducibility and standardization are important. Bioprinting offers not only automated standardizable processes but also the production of complex tissue-like structures in an additive manner. We developed an all-in-one bioprinting solution to produce soft tissue models. The holistic approach included (1) a bioprinter in a sterile environment, (2) a light-induced bioink polymerization unit, (3) a user-friendly software, (4) the capability to print in standard labware for high-throughput screening, (5) cell-compatible inkjet-based printheads, (6) a cell-compatible ready-to-use BioInk, and (7) standard operating procedures. In a proof-of-concept study, skin as a reference soft tissue model was printed. To produce dermal equivalents, primary human dermal fibroblasts were printed in alternating layers with BioInk and cultured for up to 7 weeks. During long-term cultures, the models were remodeled and fully populated with viable and spreaded fibroblasts. Primary human dermal keratinocytes were seeded on top of dermal equivalents, and epidermis-like structures were formed as verified with hematoxylin and eosin staining and immunostaining. However, a fully stratified epidermis was not achieved. Nevertheless, this is one of the first reports of an integrative bioprinting strategy for industrial routine application. © 2015 Society for Laboratory Automation and Screening.

Substance P restores normal skin architecture and reduces epidermal infiltration of sensory nerve fiber in TNCB-induced atopic dermatitis-like lesions in NC/Nga mice.

PubMed

Choi, Hyeongwon; Kim, Dong-Jin; Nam, Seungwoo; Lim, Sunki; Hwang, Jae-Sung; Park, Ki Sook; Hong, Hyun Sook; Won, Younsun; Shin, Min Kyung; Chung, Eunkyung; Son, Youngsook

2018-03-01

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by intense pruritus and eczematous lesion. Substance P (SP) is an 11-amino-acid endogenous neuropeptide that belongs to the tachykinin family and several reports recently have supported the anti-inflammatory and tissue repairing roles of SP. In this study, we investigated whether SP can improve AD symptoms, especially the impaired skin barrier function, in 2, 4, 6-trinitrochlorobenzene (TNCB)-induced chronic dermatitis of NC/Nga mice or not. AD-like dermatitis was induced in NC/Nga mice by repeated sensitization with TNCB for 5 weeks. The experimental group designations and topical treatments were as follows: vehicle group (AD-VE); SP group (AD-SP); and SP with NK1R antagonist CP99994 (AD-SP-A) group. Histological analysis was performed to evaluate epidermal differentiation, dermal integrity, and epidermal nerve innervation in AD-like lesions. The skin barrier functions and pruritus of NC/Nga mice were evaluated by measuring transepidermal water loss (TEWL) and scratching behavior, respectively. Topical SP treatment resulted in significant down-regulation of Ki67 and the abnormal-type keratins (K) K6, K16, and K17, restoration of filaggrin and claudin-1, marked reduction of TEWL, and restoration of basement membrane and dermal collagen deposition, even under continuous sensitization of low dose TNCB. In addition, SP significantly reduced innervation of itch-evoking nerve fibers, gelatinase activity and nerve growth factor (NGF) expression in the epidermis but upregulated semaphorin-3A (Sema3A) expression in the epidermis, along with reduced scratching behavior in TNCB-treated NC/Nga mice. All of these effects were completely reversed by co-treatment with the NK1R antagonist CP99994. In cultured human keratinocytes, SP treatment reduced expression of TGF-α, but upregulated TGF-β and Sema3A. Topically administered SP can restore normal skin barrier function, reduce epidermal infiltration of itch-evoking nerve fibers in the AD-like skin lesions, and alleviate scratching behavior. Thus, SP may be proposed as a potential medication for chronic dermatitis and AD. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

Cross-immunoreactivity between the LH1 antibody and cytokeratin epitopes in the differentiating epidermis of embryos of the grass snake Natrix natrix L. during the end stages of embryogenesis.

PubMed

Swadźba, Elwira; Rupik, Weronika

2012-01-01

The monoclonal anti-cytokeratin 1/10 (LH1) antibody recognizing K1/K10 keratin epitopes that characterizes a keratinized epidermis of mammals cross-reacts with the beta and Oberhäutchen layers covering the scales and gastrosteges of grass snake embryos during the final period of epidermis differentiation. The immunolocalization of the anti-cytokeratin 1/10 (LH1) antibody appears in the beta layer of the epidermis, covering the outer surface of the gastrosteges at the beginning of developmental stage XI, and in the beta layer of the epidermis, covering the outer surface of the scales at the end of developmental stage XI. This antibody cross-reacts with the Oberhäutchen layers in the epidermis covering the outer surface of both scales and gastrosteges at developmental stages XI and XII just before its fusion with the beta layers. After fusion of the Oberhäutchen and beta layers, LH1 immunolabeling is weaker than before. This might suggest that alpha-keratins in these layers of the epidermis are masked by beta-keratins, modified, or degraded. The anti-cytokeratin 1/10 (LH1) antibody stains the Oberhäutchen layer in the epidermis covering the inner surface of the gastrosteges and the hinge regions between gastrosteges at the end of developmental stage XI. However, the Oberhäutchen of the epidermis covering the inner surfaces of the scales and the hinge regions between scales does not show cytokeratin 1/10 (LH1) immunolabeling until hatching. This cross-reactivity suggests that the beta and Oberhäutchen layers probably contain some alpha-keratins that react with the LH1 antibody. It is possible that these alpha-keratins create specific scaffolding for the latest beta-keratin deposition. It is also possible that the LH1 antibody cross-reacts with other epidermal proteins such as filament-associated proteins, i.e., filaggrin-like. The anti-cytokeratin 1/10 (LH1) antibody does not stain the alpha and mesos layers until hatching. We suppose that the differentiation of these layers will begin just after the first postnatal sloughing.

MUTZ-3 derived Langerhans cells in human skin equivalents show differential migration and phenotypic plasticity after allergen or irritant exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kosten, Ilona J.; Spiekstra, Sander W.; Gruijl, Tanja D. de

After allergen or irritant exposure, Langerhans cells (LC) undergo phenotypic changes and exit the epidermis. In this study we describe the unique ability of MUTZ-3 derived Langerhans cells (MUTZ-LC) to display similar phenotypic plasticity as their primary counterparts when incorporated into a physiologically relevant full-thickness skin equivalent model (SE-LC). We describe differences and similarities in the mechanisms regulating LC migration and plasticity upon allergen or irritant exposure. The skin equivalent consisted of a reconstructed epidermis containing primary differentiated keratinocytes and CD1a{sup +} MUTZ-LC on a primary fibroblast-populated dermis. Skin equivalents were exposed to a panel of allergens and irritants. Topicalmore » exposure to sub-toxic concentrations of allergens (nickel sulfate, resorcinol, cinnamaldehyde) and irritants (Triton X-100, SDS, Tween 80) resulted in LC migration out of the epidermis and into the dermis. Neutralizing antibody to CXCL12 blocked allergen-induced migration, whereas anti-CCL5 blocked irritant-induced migration. In contrast to allergen exposure, irritant exposure resulted in cells within the dermis becoming CD1a{sup −}/CD14{sup +}/CD68{sup +} which is characteristic of a phenotypic switch of MUTZ-LC to a macrophage-like cell in the dermis. This phenotypic switch was blocked with anti-IL-10. Mechanisms previously identified as being involved in LC activation and migration in native human skin could thus be reproduced in the in vitro constructed skin equivalent model containing functional LC. This model therefore provides a unique and relevant research tool to study human LC biology in situ under controlled in vitro conditions, and will provide a powerful tool for hazard identification, testing novel therapeutics and identifying new drug targets. - Highlights: • MUTZ-3 derived Langerhans cells integrated into skin equivalents are fully functional. • Anti-CXCL12 blocks allergen-induced MUTZ-LC migration. • Anti-CCL5 blocks irritant-induced MUTZ-LC migration. • Irritant mediated MUTZ-LC trans-differentiation to macrophage-like cell in dermis. • Trans-differentiation of MUTZ-LC is IL-10 dependent.« less

Two-photon excited fluorescence spectroscopy and imaging of melanin in vitro and in vivo

NASA Astrophysics Data System (ADS)

Krasieva, Tatiana B.; Liu, Feng; Sun, Chung-Ho; Kong, Yu; Balu, Mihaela; Meyskens, Frank L.; Tromberg, Bruce J.

2012-03-01

The ability to detect early melanoma non-invasively would improve clinical outcome and reduce mortality. Recent advances in two-photon excited fluorescence (TPEF) in vivo microscopy offer a powerful tool in early malignant melanoma diagnostics. The goal of this work was to develop a TPEF optical index for measuring relative concentrations of eumelanin and pheomelanin since ex vivo studies show that changes in this ratio have been associated with malignant transformation. We acquired TPEF emission spectra (λex=1000 nm) of melanin from several specimens, including human hair, malignant melanoma cell lines, and normal melanocytes and keratinocytes in different skin layers (epidermis, papillary dermis) in five healthy volunteers in vivo. We found that the pheomelanin emission peaks at around 620 nm and is blue-shifted from the eumelanin with broad maximum at 640-680nm. We defined "optical melanin index" (OMI) as a ratio of fluorescence signal intensities measured at 645 nm and 615nm. The measured OMI for a melanoma cell line MNT-1 was 1.6+/-0.2. The MNT-46 and MNT-62 lines (Mc1R gene knockdown) showed an anticipated change in melanins production ratio and had OMI of 0.55+/-0.05 and 0.17+/-0.02, respectively, which strongly correlated with HPLC data obtained for these lines. Average OMI measured for basal cells layers (melanocytes and keratinocytes) in normal human skin type I, II-III (not tanned and tanned) in vivo was 0.5, 1.05 and 1.16 respectively. We could not dependably detect the presence of pheomelanin in highly pigmented skin type V-VI. These data suggest that a non-invasive TPEF index could potentially be used for rapid melanin ratio characterization both in vitro and in vivo, including pigmented lesions.

Regeneration of the epidermis and basement membrane of the planarian Dugesia japonica after total-body x irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hori, I.

1979-03-01

Fresh-water planarians were studied to examine effects of x rays on regeneration of the epidermis and basement membrane. During early stages of regeneration, free rhabdite-forming cells were associated with the wound epidermis and recruited it. In later stages, however, a gradual degeneration occurred in the epidermis and cells undergoing epithelization decreased in number. Eventually epidermal cells on the wound surface appeared necrotic as evidenced by pyknotic nuclei and vacuolized dense cytoplasm. The entire basement membrane could not be reconstituted in any stage after wounding though its precursor-like material was secreted in the interspace between epidermis and parenchyma. Morphological changes inmore » extracellular products and in the cells surrounding the products suggest that epidermal cells which have covered the wound surface synthesize precursors of the basement membrane. Possible factors of a characteristic perturbation in epithelization and basement membrane formation after total-body irradiation are discussed.« less

Effects of Hydroxydecine(®) (10-hydroxy-2-decenoic acid) on skin barrier structure and function in vitro and clinical efficacy in the treatment of UV-induced xerosis.

PubMed

Duplan, Hélène; Questel, Emmanuel; Hernandez-Pigeon, Hélène; Galliano, Marie Florence; Caruana, Antony; Ceruti, Isabelle; Ambonati, Marco; Mejean, Carine; Damour, Odile; Castex-Rizzi, Nathalie; Bessou-Touya, Sandrine; Schmitt, Anne-Marie

2011-01-01

10-Hydroxy-2-decenoic acid, a natural fatty acid only found in royal jelly, may be of value in correcting skin barrier dysfunction. We evaluated the activity of Hydroxydecine(®), its synthetic counterpart, in vitro on the regulation of epidermal differentiation markers, ex vivo on the inflammatory response and restoration of skin barrier function, and in vivo on UV-induced xerosis in healthy human volunteers. In cultured normal human keratinocytes, Hydroxydecine(®) induced involucrin, transglutaminase-1 and filaggrin protein production. In topically Hydroxydecine(®)-treated skin equivalents, immunohistochemical analysis revealed an increase in involucrin, transglutaminase-1 and filaggrin staining. In a model of thymic stromal lymphopoietin (TSLP)-induced inflamed epidermis, a Hydroxydecine(®)-containing emulsion inhibited TSLP release. In a model of inflammation and barrier impairment involving human skin explants maintained alive, Hydroxydecine(®) balm restored stratum corneum cohesion and significantly increased filaggrin expression, as shown by immunohistochemistry. It also decreased pro-inflammatory cytokine secretion (IL-4, IL-5 and IL-13). In healthy volunteers with UV-induced xerosis, the hydration index increased by +28.8% (p<0.01) and +60.4% (p<0.001) after 7 and 21 days of treatment with Hydroxydecine(®) cream, respectively. Hydroxydecine(®) thus proved its efficacy in activating keratinocyte differentiation processes in vitro, restoring skin barrier function and reducing inflammation ex vivo, and hydrating dry skin in vivo.

Epithelial-mesenchymal transition in keloid tissues and TGF-β1-induced hair follicle outer root sheath keratinocytes.

PubMed

Yan, Li; Cao, Rui; Wang, Lianzhao; Liu, Yuanbo; Pan, Bo; Yin, Yanhua; Lv, Xiaoyan; Zhuang, Qiang; Sun, Xuejian; Xiao, Ran

2015-01-01

Keloid is a skin fibrotic disease with the characteristics of recurrence and invasion, its pathogenesis still remains unrevealed. The epithelial-mesenchymal transition (EMT) is critical for wound healing, fibrosis, recurrence, and invasion of cancer. We sought to investigate the EMT in keloid and the mechanism through which the EMT regulates keloid formation. In keloid tissues, the expressions of EMT-associated markers and transforming growth factor (TGF)-β1/Smad3 signaling were examined by immunohistochemistry. In the keloid epidermis and dermal tissue, the expressions of genes related to the regulation of skin homeostasis, fibroblast growth factor receptor 2 (FGFR2) and p63, were analyzed using quantitative real-time polymerase chain reaction. The results showed that accompanying the loss of the epithelial marker E-cadherin and the gain of the mesenchymal markers fibroblast-specific protein 1 (FSP1) and vimentin in epithelial cells from epidermis and skin appendages, and in endothelial cells from dermal microvessels, enhanced TGF-β1 expression and Smad3 phosphorylation were noted in keloid tissues. Moreover, alternative splicing of the FGFR2 gene switched the predominantly expressed isoform from FGFR2-IIIb to -IIIc, concomitant with the decreased expression of ΔNp63 and TAp63, which changes might partially account for abnormal epidermis and appendages in keloids. In addition, we found that TGF-β1-induced hair follicle outer root sheath keratinocytes (ORSKs) and normal skin epithelial cells underwent EMT in vitro with ORSKs exhibiting more obvious EMT changes and more similar expression profiles for EMT-associated and skin homeostasis-related genes as in keloid tissues, suggesting that ORSKs might play crucial roles in the EMT in keloids. Our study provided insights into the molecular mechanisms mediating the EMT pathogenesis of keloids. © 2015 by the Wound Healing Society.

The differential expression of VEGF, VEGFR-2, and GLUT-1 proteins in disease subtypes of systemic sclerosis.

PubMed

Davies, Christine Ann; Jeziorska, Maria; Freemont, Anthony J; Herrick, Ariane L

2006-02-01

Our aim was to evaluate (a) whether there is differential expression of the endothelial regulator vascular endothelial growth factor (VEGF), its receptor (VEGFR-2), and the hypoxia-associated glucose transporter molecule, GLUT-1, in skin biopsies from different disease subtypes of systemic sclerosis (SSc) and (b) whether they associate with dermal calcinosis, a significant complication of SSc. Skin punch biopsies were taken from the forearms of 66 SSc patients including 18 with limited cutaneous disease without calcinosis (lcSSc), 23 with calcinosis (lcSSc/cal), and 25 with diffuse cutaneous disease (dcSSc) and from 12 healthy control subjects. The histological appearance of the skin was graded as G0 (normal), G1 (dermal edema), or G2 or G3 (increasing fibrotic changes). Immunohistochemistry was performed with antibodies to VEGF, VEGFR-2, and GLUT-1. Staining was assessed in the epidermis, microvessels, and fibroblasts. The Kruskal-Wallis 1-way analysis of variance was used to compare the data between disease groups. VEGF protein was located in the epidermis and in dermal endothelial cells, pericytes, fibroblasts, and inflammatory cells. In dcSSc only, there was a significant increase in VEGF staining intensity in the keratinocytes and pericytes and the lowest percentage of microvessels with VEGF-positive endothelial cells. GLUT-1 protein was located in the epidermis, erythrocytes, and perineurium. In both lcSSc/cal and dcSSC, but not lcSSc, there were significant increases in GLUT-1 staining intensity of keratinocytes. We propose that in patients with dcSSc, there is a net increase in unbound VEGF in skin that may account for the raised levels of VEGF in serum reported by others. Increased GLUT-1 expression in lcSSc/cal and dcSSc indicates that hypoxia is an associated factor.

Integrated Experimental and Computational Approach to Understand the Effects of Heavy Ion Radiation on Skin Homeostasis.

DOE Office of Scientific and Technical Information (OSTI.GOV)

von Neubeck, Claere; Shankaran, Harish; Geniza, Matthew

2013-08-08

The effects of low dose high linear energy transfer (LET) radiation on human health are of concern for both space and clinical exposures. As epidemiological data for such radiation exposures are scarce for making relevant predictions, we need to understand the mechanism of response especially in normal tissues. Our objective here is to understand the effects of heavy ion radiation on tissue homeostasis in a realistic model system. Towards this end, we exposed an in vitro three dimensional skin equivalent to low fluences of Neon (Ne) ions (300 MeV/u), and determined the differentiation profile as a function of time followingmore » exposure using immunohistochemistry. We found that Ne ion exposures resulted in transient increases in the tissue regions expressing the differentiation markers keratin 10, and filaggrin, and more subtle time-dependent effects on the number of basal cells in the epidermis. We analyzed the data using a mathematical model of the skin equivalent, to quantify the effect of radiation on cell proliferation and differentiation. The agent-based mathematical model for the epidermal layer treats the epidermis as a collection of heterogeneous cell types with different proliferation/differentiation properties. We obtained model parameters from the literature where available, and calibrated the unknown parameters to match the observed properties in unirradiated skin. We then used the model to rigorously examine alternate hypotheses regarding the effects of high LET radiation on the tissue. Our analysis indicates that Ne ion exposures induce rapid, but transient, changes in cell division, differentiation and proliferation. We have validated the modeling results by histology and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The integrated approach presented here can be used as a general framework to understand the responses of multicellular systems, and can be adapted to other epithelial tissues.« less

The Effect of Maternal Thyroid Disorders (Hypothyroidism and Hyperthyroidism) During Pregnancy and Lactation on Skin Development in Wistar Rat Newborns

PubMed Central

Amerion, Maryam; Tahajjodi, Somayye; Hushmand, Zahra; Mahdavi Shahri, Nasser; Nikravesh, Mohammad Reza; Jalali, Mahdi

2013-01-01

Objective(s): Previous studies have shown that thyroid hormones are necessary for normal development of many organs and because of the importance of skin as the largest and the most important organ in human body protection in spite of external environment, the study of thyroid hormones effects on skin development is considerable. In this survey we have tried to study the effects of maternal hypothyroidism on skin development in fetus during pregnancy and lactation by immunohistochemistry technique. Materials and Methods: Rats were divided into 4 groups, hypothyroids, hyperthyroids, hypothyroids are treated with levothyroxin and a control group. The rat mothers were exposed to PTU with 50 mg/lit dosage and levothyroxin with 1 mg/lit dosage and PTU and levothyroxin simultaneously and with the same dosage respectively in hypothyroid, hyperthyroid and treated hypothyroids with levothyroxin groups. After 14 days, blood sample was taken from mothers, and if thyroid hormones level had change well, mating was allowed. After pregnancy and delivery, 1th day dorsal skin (as the sample for pregnancy assay) and 10th day skin (as for lactation assay) was used for immunohystochemical and morphometric studies. Results: In this study it was observed that maternal hypothyroidism during pregnancy and lactation causes significant increase in laminin expression, in most areas of skin, and maternal hyperthyroidism during pregnancy and lactation causes significant decrease in laminin expression. Also significant decrease was observed in hair follicles number and epidermis thickness in hypothyroidism groups. Conclusion: This study showed maternal hypothyroidism causes significant decrease in epidermis thickness and hair follicles number and it causes less hair in fetus. Also maternal hypothyroidism causes large changes in laminin expression in different parts of skin. At the same time,maternal hyperthyroidism causes opposite results. In fact, thyroid hormones regulate laminin expression negatively which means increase in thyroid hormone level, decreases laminin expression. So changes in thyroid hormones level can influence skin development significantly. PMID:23826487

Metabolic-morphologic characteristics of the integument of teleost fish with mature lymphocystis nodules.

PubMed

Spitzer, R H; Koch, E A; Reid, R B; Downing, S W

1982-01-01

Normal and virus-infected (lymphocystis disease) integument from five species of teleosts was examined by light and TEM autoradiography and SEM to establish metabolic-morphologic characteristics of integument with mature lymphocystis cells (LC's). LC's with numerous morphologic attributes of a late developmental stage showed highest incorporation of [3H]-thymidine in vivo (1-91 h) above the intracytoplasmic inclusion body (ci) with little radiolabel in nuclei, cytoplasmic icosahedral deoxyriboviruses (ICDV's) or capsule. Analysis by quantitative autoradiography revealed that the % total cell label in ci and cytoplasm did not vary appreciably from 1-91 h and was corroborative with morphologic criteria of maturity. A possibly phylogenetic difference was noted between teleosts, wherein normal integument showed uptake of [3H]-thymidine in vivo (1 h) by cells at all levels of the epidermis, and cyclostomes (Spitzer et al. 1979) wherein labeling was confined to the basal third of the epidermis. Among four infected teleost species, the mean diameters of the ICDV's measured under the same conditions, ranged from 259.5 nm to 290.0 nm with the mean for each species differing significantly (p less than 0.01) from each of the other means. Ruptured LC's were shown by TEM and SEM to have released ICDV's onto the lesions and integument. Various stages of LC degeneration, host response, and integumental repair processes were documented. An evaluation of labeling in vivo of the capsular matrix was compatible ([3H]-D-galactose greater than [3H]-L-lysine much greater than [3H]-L-fucose) with a glycosaminoglycan-protein structure.

Coordinate expression of cytokeratins 7 and 14, vimentin, and Bcl-2 in canine cutaneous epithelial tumors and cysts.

PubMed

Pieper, Jason B; Stern, Adam W; LeClerc, Suzette M; Campbell, Karen L

2015-07-01

Forty-seven canine cutaneous epithelial tumors and cysts were examined to determine coordinate expression of cytokeratins 7 (CK7) and 14 (CK14), vimentin, and Bcl-2 using commercially available antibodies. Within non-affected normal skin adjacent to tumors or cysts, CK7 expression was observed in luminal cells in apocrine glands; CK14 expression was observed in the stratum basale, stratum spinosum, stratum granulosum, basal layer of outer root sheath, sebaceous glands, and myoepithelial cells of apocrine glands; vimentin expression was observed in dermal papilla and scattered non-epithelial cells within the epidermis; and Bcl-2 expression was observed in scattered non-epithelial cells in the epidermis and some apocrine glands. The pattern of expression of CK7 and CK14 in cases of adenocarcinoma of the apocrine gland of the anal sac (CK7+/CK14-) and hepatoid gland tumors (CK7-/CK14+) may prove useful for diagnostic purposes. Loss of expression of CK14 and vimentin, identifying myoepithelial cells, was observed in apocrine and ceruminous adenocarcinomas. Differences in patterns of expression of Bcl-2 were observed between infundibular keratinizing acanthomas compared to trichoepitheliomas. © 2015 The Author(s).

Influence of human fibroblasts on development and quality of multilayered composite grafts in athymic nude mice.

PubMed

Cedidi, C Can; Wilkens, L; Berger, A; Ingianni, G

2007-11-05

In patients after extensive burn injury the lack of split thickness skin graft donor sites, and consecutive delay in wound closure are critical factors of morbidity and mortality. In addition limited functional and aesthetic results after transplantation of split thickness skin grafts present a socioeconomic problem. For improved wound closure the aim of this study was the development of a one stage technique for the establishment of a multi layer composite graft, existing of a collagen-GAG-matrix with silicon layer of a two layer synthetic dermal equivalent (DE) with integrated fibroblasts, and ceratinocytes. - In 64 athymic nude mice the evaluation of the multi layer skin grafts potential to re-establish a human epidermis, and high quality dermal structure was performed. In addition to clinical investigations we measured wound contraction, and analyzed histomorphologic, immunohistologic, "in situ hybridisation", and electro microscopic data. - Our results show, that the seeding of DE with human fibroblasts and ceratinocytes as a composite skin graft reproducible enabled a wound healing with an organised human dermis and epidermis within 10 - 15 days. The histological studies of the grafted composite skin grafts in this model showed morphologically a characteristic dermal-epidermal skin structure with a cornifying epithelium, being of human origin ("in situ hybridisation"). Through the co-cultivation of fibroblasts and ceratinocytes in the DE the generation and structural morphology of collagen fibres, and inflammatory reaction in the neodermis is positively influenced, and as a consequence wound contraction significantly reduced. In regard to the early preparation of composite grafts, and the minimal requirements for donor sites - with dependable stable reconstruction of the integument - this technique may present a step forward in the treatment of patients with extensive burns.

Lowering relative humidity level increases epidermal protein deimination and drives human filaggrin breakdown.

PubMed

Cau, Laura; Pendaries, Valérie; Lhuillier, Emeline; Thompson, Paul R; Serre, Guy; Takahara, Hidenari; Méchin, Marie-Claire; Simon, Michel

2017-05-01

Deimination (also known as citrullination), the conversion of arginine in a protein to citrulline, is catalyzed by a family of enzymes called peptidylarginine deiminases (PADs). Three PADs are expressed in the epidermis, one of their targets being filaggrin. Filaggrin plays a central role in atopic dermatitis and is a key protein for the epidermal barrier. It aggregates keratins and is cross-linked to cornified envelopes. Following its deimination, it is totally degraded to release free amino acids, contributing to the natural moisturizing factor (NMF). The mechanisms controlling this multistep catabolism in human are unknown. To test whether external humidity plays a role, and investigate the molecular mechanisms involved. Specimens of reconstructed human epidermis (RHEs) produced in humid or dry conditions (>95% or 30-50% relative humidity) were compared. RHEs produced in the dry condition presented structural changes, including a thicker stratum corneum and a larger amount of keratohyalin granules. The transepidermal water loss and the stratum corneum pH were decreased whereas the quantity of NMF was greater. This highly suggested that filaggrin proteolysis was up-regulated. The expression/activity of the proteases involved in filaggrin breakdown did not increase while PAD1 expression and the deimination rate of proteins, including filaggrin, were drastically enhanced. Partial inhibition of PADs with Cl-amidine reversed the effect of dryness on filaggrin breakdown. These results demonstrate the importance of external humidity in the control of human filaggrin metabolism, and suggest that deimination plays a major role in this regulation. Copyright © 2017 Japanese Society for Investigative Dermatology. All rights reserved.

The impact of epidermal melanin on objective measurements of human skin colour.

PubMed

Alaluf, Simon; Atkins, Derek; Barrett, Karen; Blount, Margaret; Carter, Nik; Heath, Alan

2002-04-01

Objective measurements of human skin colour were made with a tristimulus (L*a*b*) chromameter in a range of different ethnic skin types. These were compared with biochemical measurements of melanin content, melanin composition and melanosome size in skin biopsies obtained from the same sites. L*, a* and b* values were found to vary significantly with ethnicity. In general, constitutively dark skin types have lower L* values, higher a* values and higher b* values than constitutively light skin types. Total epidermal melanin content appears to be the primary determinant of L* values in human skin (r = -0.88; P < 0.00001), whilst melanosome size also has a significant but more subtle influence on L* values (r = -0.73; P < 0.00001). There is also a strong positive contribution to a* values from epidermal melanin (r = 0.66, P < 0.00001), which accounts for the ethnic variation in a* values observed in this study. Melanin is also a major contributor to b* values in lighter skin types (r = 0.71, P < 0.00001). However, this relationship breaks down in darker skin types where b* values actually reach a maximum and then decrease as the concentration of melanin in the skin increases. This appears to be because of optical masking of yellow light by high concentrations of melanin in the epidermis. Analysis of the relationships between L*, a* and b* values in human skin indicate that they are very closely interrelated, and suggest that the optical properties of melanin in the epidermis are very similar to those of a dye on a fabric substrate.

The expression and regulation of enzymes mediating the biosynthesis of triglycerides and phospholipids in keratinocytes/epidermis

PubMed Central

Feingold, Kenneth R

2011-01-01

Triglycerides and phospholipids play an important role in epidermal permability barrier formation and function. They are synthesized de novo in the epidermis via the glycerol-3-phosphate pathway, catalyzed sequentially by a group of enzymes that have multiple isoforms including glycerol-3-phosphate acyltransferase (GPAT), 1-acylglycerol-3-phosphate acyltransferase (AGPAT), Lipin and diacylglycerol acyltransferase (DGAT). Here we review the current knowledge of GPAT, AGPAT, Lipin and DGAT enzymes in keratinocytes/epidermis focusing on the expression levels of the various isoforms and their localization in mouse epidermis. Additionally, the factors regulating their gene expression, including calcium induced differentiation, PPAR and LXR activators, and the effect of acute permeability barrier disruption will be discussed. PMID:21695015

Isolation and characterization of a cDNA encoding a membrane bound acyl-CoA binding protein from Agave americana L. epidermis.

PubMed

Guerrero, Consuelo; Martín-Rufián, M; Reina, José J; Heredia, Antonio

2006-01-01

A cDNA encoding an acyl-CoA binding protein (ACBP) homologue has been cloned from a cDNA library made from mRNA isolated from epidermis of young leaves of Agave americana L. The derived amino acid sequence reveals a protein corresponding to the membrane-associated form of ACBPs only previously described in Arabidopsis and rice. Northern blot analysis showed that the A. americana ACBP gene is mainly expressed in the epidermis of mature zone of the leaves. The epidermis of A. americana leaves have a well developed cuticle with the highest amounts of the cuticular components waxes, cutin and cutan suggesting a potential role of the protein in cuticle formation.

Development of paclitaxel-TyroSpheres for topical skin treatment

PubMed Central

Kilfoyle, Brian E.; Sheihet, Larisa; Zhang, Zheng; Laohoo, Marissa; Kohn, Joachim; Michniak-Kohn, Bozena B.

2012-01-01

A potential topical psoriasis therapy has been developed consisting of tyrosine-derived nanospheres (TyroSpheres) with encapsulated anti-proliferative paclitaxel. TyroSpheres provide enhancement of paclitaxel solubility (almost 4,000 times greater than PBS) by effective encapsulation and enable sustained, dose-controlled release over 72 hours under conditions mimicking skin permeation. TyroSpheres offer potential in the treatment of psoriasis, a disease resulting from over-proliferation of keratinocytes in the basal layer of the epidermis, by (a) enabling delivery of paclitaxel into the epidermis at concentrations >100 ng/cm2 of skin surface area and (b) enhancing the cytotoxicity of loaded paclitaxel to human keratinocytes (IC50 of paclitaxel-TyroSpheres was approximately 45% lower than that of free paclitaxel). TyroSpheres were incorporated into a gel-like viscous formulation to improve their flow characteristics with no impact on homogeneity, release or skin distribution of the payload. The findings reported here confirm that the TyroSpheres provide a platform for paclitaxel topical administration allowing skin drug localization and minimal systemic escape. PMID:22732474

Fetal Therapy Model of Myelomeningocele with Three-Dimensional Skin Using Amniotic Fluid Cell-Derived Induced Pluripotent Stem Cells.

PubMed

Kajiwara, Kazuhiro; Tanemoto, Tomohiro; Wada, Seiji; Karibe, Jurii; Ihara, Norimasa; Ikemoto, Yu; Kawasaki, Tomoyuki; Oishi, Yoshie; Samura, Osamu; Okamura, Kohji; Takada, Shuji; Akutsu, Hidenori; Sago, Haruhiko; Okamoto, Aikou; Umezawa, Akihiro

2017-06-06

Myelomeningocele (MMC) is a congenital disease without genetic abnormalities. Neurological symptoms are irreversibly impaired after birth, and no effective treatment has been reported to date. Only surgical repairs have been reported so far. In this study, we performed antenatal treatment of MMC with an artificial skin using induced pluripotent stem cells (iPSCs) generated from a patient with Down syndrome (AF-T21-iPSCs) and twin-twin transfusion syndrome (AF-TTTS-iPSCs) to a rat model. We manufactured three-dimensional skin with epidermis generated from keratinocytes derived from AF-T21-iPSCs and AF-TTTS-iPSCs and dermis of human fibroblasts and collagen type I. For generation of epidermis, we developed a protocol using Y-27632 and epidermal growth factor. The artificial skin was successfully covered over MMC defect sites during pregnancy, implying a possible antenatal surgical treatment with iPSC technology. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Effects of CuO nanoparticles on insecticidal activity and phytotoxicity in conventional and transgenic cotton.

PubMed

Van, Nhan Le; Ma, Chuanxin; Shang, Jianying; Rui, Yukui; Liu, Shutong; Xing, Baoshan

2016-02-01

Nanoparticles and transgenic plants are recent scientific developments that require systematic study to understand their potential risks to human health. The effects of CuO nanoparticles (NPs) on Bt-transgenic cotton and conventional cotton are reported here. CuO NPs inhibited the growth, development, nutrient content, and indole-3-acetic acid (IAA) and abscisic acid (ABA) concentrations of transgenic and conventional cotton. Transmission electron microscopy (TEM) images showed CuO NPs aggregated on the epidermis of conventional cotton leaves, whereas it had reached into the cells of transgenic cotton leaves by endocytosis. Most CuO NPs aggregates were found on the root outer epidermis and the rest were located in intercellular spaces of both conventional and Bt-transgenic cottons. CuO NPs enhanced the expression of the exogenous gene encoding of Bt toxin protein in leaves and roots, especially at low CuO NP concentrations, providing an important benefit for Bt cotton insect resistance. Copyright © 2015 Elsevier Ltd. All rights reserved.

USSR and Eastern Europe Scientific Abstracts Biomedical and Behavioral Sciences No. 76

DTIC Science & Technology

1977-08-19

radius around that. Histologically, indications of coagulation necrosis are found, with honeycomb-like expansion of the epidermis and other changes...eaten by the local residents, diphyllobothriasis is passed on to the human population. A number of therapeutic and prophylactic measures are proposed...means of a direct method, measurement of the pressure within the bladder upon excitation by audio frequency signals. The fish were anesthetized

Genome-wide expression analysis of human in vivo irritated epidermis: differential profiles induced by sodium lauryl sulfate and nonanoic acid.

PubMed

Clemmensen, Anders; Andersen, Klaus E; Clemmensen, Ole; Tan, Qihua; Petersen, Thomas K; Kruse, Torben A; Thomassen, Mads

2010-09-01

The pathogenesis of irritant contact dermatitis (ICD) is poorly understood, and genes participating in the epidermal response to chemical irritants are only partly known. It is commonly accepted that different irritants have different mechanisms of action in the development of ICD. To define the differential molecular events induced in the epidermis by different irritants, we collected sequential biopsies ((1/2), 4, and 24 hours after a single exposure and at day 11 after repeated exposure) from human volunteers exposed to either sodium lauryl sulfate (SLS) or nonanoic acid (NON). Gene expression analysis using high-density oligonucleotide microarrays (representing 47,000 transcripts) revealed essentially different pathway responses (1/2)hours after exposure: NON transiently induced the IL-6 pathway as well as a number of mitogen-activated signaling cascades including extracellular signal-regulated kinase and growth factor receptor signaling, whereas SLS transiently downregulated cellular energy metabolism pathways. Differential expression of the cyclooxygenase-2 and matrix metalloproteinase 3 transcripts was confirmed immunohistochemically. After cumulative exposure, 883 genes were differentially expressed, whereas we identified 23 suggested common biomarkers for ICD. In conclusion, we bring new insights into two hitherto less well-elucidated phases of skin irritancy: the very initial as well as the late phase after single and cumulative mild exposures, respectively.

Percutaneous permeation comparison of repellents picaridin and DEET in concurrent use with sunscreen oxybenzone from commercially available preparations.

PubMed

Chen, T; Burczynski, F J; Miller, D W; Gu, X

2010-11-01

Concurrent application of insect repellent picaridin or DEET with sunscreens has become prevalent due to concerns on West Nile virus and skin cancer. The objectives of this study were to characterize the percutaneous permeation of picaridin and sunscreen oxybenzone from commercially available preparations and to compare the differences in permeability between picaridin and DEET in association with oxybenzone. In vitro diffusion studies were carried out to measure transdermal permeation of picaridin and oxybenzone from four different products, using various application concentrations and sequences. Results were then compared to those of repellent DEET and sunscreen oxybenzone under identical conditions. Transdermal permeation of picaridin across human epidermis was significantly lower than that of DEET, both alone and in combination with oxybenzone. Concurrent use resulted in either no changes or suppression of transdermal permeation of picaridin and oxybenzone. This finding was different from concurrent use of DEET and oxybenzone in which a synergistic permeation enhancement was observed. In addition, permeation of picaridin, DEET and oxybenzone across human epidermis was dependent on application concentration, use sequence, and preparation type. It was concluded from this comparative study that picaridin would be a better candidate for concurrent use with sunscreen preparations in terms of minimizing percutaneous permeation of the chemicals.

Skin permeability and local tissue concentrations of nonsteroidal anti-inflammatory drugs after topical application.

PubMed

Singh, P; Roberts, M S

1994-01-01

Nonsteroidal anti-inflammatory drugs (NSAIDs) are being administered increasingly by transdermal drug delivery for the treatment of local muscle inflammation. The human epidermal permeabilities of different NSAIDs (salicylic acid, diethylamine salicylate, indomethacin, naproxen, diclofenac and piroxicam) from aqueous solutions is dependent on the drug's lipophilicity. A parabolic relationship was observed when the logarithms of NSAID permeability coefficients were plotted against the logarithms of NSAID octanol-water partition coefficients (log P), the optimum log P being around 3. The local tissue concentrations of these drugs after dermal application in aqueous solutions were then determined in a rat model. The extent of local, as distinct from systemic delivery, for each NSAID was assessed by comparing the tissue concentrations obtained below a treated site to those in contralateral tissues. Local direct penetration was evident for all NSAIDs up to a depth of about 3 to 4 mm below the applied site, with distribution to deeper tissues being mainly through the systemic blood supply. A comparison of the predicted tissue concentrations of each NSAID after its application to human epidermis was then made by a convolution of the epidermal and underlying tissue concentration-time profiles. The estimated tissue concentrations after epidermal application of NSAIDs could be related to their maximal fluxes across epidermis from an applied vehicle.

TLRs to cytokines: mechanistic insights from the imiquimod mouse model of psoriasis.

PubMed

Flutter, Barry; Nestle, Frank O

2013-12-01

Psoriasis is an inflammatory disease of the skin affecting 2-3% of the population, characterized by a thickening of the epidermis and immune infiltrates throughout the dermis and epidermis, causing skin lesions that can seriously affect quality of life. The study of psoriasis has historically been hampered by the lack of good animal models. Various genetically induced models exist, which have provided some information about possible mechanisms of disease, but these models rely mostly on intrinsic imbalances of homeostasis. However, a mouse model of psoriasiform dermatitis caused by the repeated topical application of Aldara™ containing 5% imiquimod was described in 2009. The mechanisms of action of Aldara™ are complex. Imiquimod is an effective ligand for TLR7 (and TLR8 in humans) and also interferes with adenosine receptor signaling. In addition, isostearic acid present in the Aldara™ vehicle has been shown to be biologically active and of importance for activating the inflammasome. Interestingly, the repetitive application of Aldara™ reveals a complex aetiology involving multiple cell types, cytokines, and inflammatory pathways. In this review, we will dissect the findings of the imiquimod model to date and ask how this model can inform us about the immunological aspects of human disease. © 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

Long-range comparison of human and mouse Sprr loci to identify conserved noncoding sequences involved in coordinate regulation

PubMed Central

Martin, Natalia; Patel, Satyakam; Segre, Julia A.

2004-01-01

Mammalian epidermis provides a permeability barrier between an organism and its environment. Under homeostatic conditions, epidermal cells produce structural proteins, which are cross-linked in an orderly fashion to form a cornified envelope (CE). However, under genetic or environmental stress, specific genes are induced to rapidly build a temporary barrier. Small proline-rich (SPRR) proteins are the primary constituents of the CE. Under stress the entire family of 14 Sprr genes is upregulated. The Sprr genes are clustered within the larger epidermal differentiation complex on mouse chromosome 3, human chromosome 1q21. The clustering of the Sprr genes and their upregulation under stress suggest that these genes may be coordinately regulated. To identify enhancer elements that regulate this stress response activation of the Sprr locus, we utilized bioinformatic tools and classical biochemical dissection. Long-range comparative sequence analysis identified conserved noncoding sequences (CNSs). Clusters of epidermal-specific DNaseI-hypersensitive sites (HSs) mapped to specific CNSs. Increased prevalence of these HSs in barrier-deficient epidermis provides in vivo evidence of the regulation of the Sprr locus by these conserved sequences. Individual components of these HSs were cloned, and one was shown to have strong enhancer activity specific to conditions when the Sprr genes are coordinately upregulated. PMID:15574822

Penetration and distribution of PLGA nanoparticles in the human skin treated with microneedles.

PubMed

Zhang, Wei; Gao, Jing; Zhu, Quangang; Zhang, Min; Ding, Xueying; Wang, Xiaoyu; Hou, Xuemei; Fan, Wei; Ding, Baoyue; Wu, Xin; Wang, Xiying; Gao, Shen

2010-12-15

This study was designed to investigate the penetration and the distribution of poly(d,l-lactic-co-glycolic acid) (PLGA) nanoparticles in the human skin treated with microneedles. Fluorescent nanoparticles were prepared to indicate the transdermal transport process of the nanoparticles. Permeation study was performed on Franz-type diffusion cells in vitro. The distribution of nanoparticles was visualized by confocal laser scanning microscopy (CLSM) and quantified by high performance liquid chromatography (HPLC). CLSM images showed that nanoparticles were delivered into the microconduits created by microneedles and permeated into the epidermis and the dermis. The quantitative determination showed that (i) the permeation of nanoparticles into the skin was enhanced by microneedles, but no nanoparticle reached the receptor solution; (ii) much more nanoparticles deposited in the epidermis than those in the dermis; (iii) the permeation was in a particle size-dependent manner; and (iv) the permeation increased with the nanoparticle concentration increasing until a limit value was reached. These results suggested that microneedles could enhance the intradermal delivery of PLGA nanoparticles. The biodegradable nanoparticles would sustain drug release in the skin and supply the skin with drug over a prolonged period. This strategy would prove to be useful for topical drug administration. Copyright © 2010 Elsevier B.V. All rights reserved.

Percutaneous absorption of sunscreen agents from liquid paraffin: self-association of octyl salicylate and effects on skin flux.

PubMed

Jiang, R; Roberts, M S; Prankerd, R J; Benson, H A

1997-07-01

This study provides an investigation of the availability of octyl salicylate (OS), a common sunscreen agent, from liquid paraffin and the effect of OS on skin permeability. A model membrane system to isolate the vehicle effect from membrane permeability has been developed. Partitioning of OS between liquid paraffin and aqueous receptor phases was conducted. Partition coefficients increased with increase in OS concentration. A range of OS concentrations in liquid paraffin was diffused across human epidermis and synthetic membranes into 4% bovine serum albumin in phosphate-buffered saline and 50% ethanol. Absorption profiles of OS obtained from silicone and low-density polyethylene (LDPE) membranes were similar to each other but higher than for the high-density polyethylene [HDPE (3 times)] membrane and human epidermis (15 times). The steady state fluxes and apparent permeability coefficients (Kp') obtained from the diffusion studies showed the same trends with all membranes, except for the HDPE membrane which showed greater increase in flux and Kp' at concentrations above 30%. IR spectra showed that several bands of OS were shifted with concentrations, and the molecular models further suggested that the main contribution to the self-association is from non-1,4 van der Waals interactions.

Simultaneous absorption of vitamins C and E from topical microemulsions using reconstructed human epidermis as a skin model.

PubMed

Rozman, Branka; Gasperlin, Mirjana; Tinois-Tessoneaud, Estelle; Pirot, Fabrice; Falson, Francoise

2009-05-01

Antioxidants provide the mainstay for skin protection against free radical damage. The structure of microemulsions (ME), colloidal thermodynamically stable dispersions of water, oil and surfactant, allows the incorporation of both lipophilic (vitamin E) and hydrophilic (vitamin C) antioxidants in the same system. The objective of this work was to investigate the potential of non-thickened (o/w, w/o and gel-like) and thickened (with colloidal silica) ME as carriers for the two vitamins using reconstructed human epidermis (RHE). The amounts of these vitamins accumulated in and permeated across the RHE were determined, together with factors affecting skin deposition and permeation. Notable differences were observed between formulations. The absorption of vitamins C and E in RHE layers was in general enhanced by ME compared to solutions. The incorporation of vitamins in the outer phase of ME resulted in greater absorption than that when vitamins were in the inner phase. The location of the antioxidants in the ME and affinity for the vehicle appear to be crucial in the case of non-thickened ME. Addition of thickener enhanced the deposition of vitamins E and C in the RHE. By varying the composition of ME, RHE absorption of the two vitamins can be significantly modulated.

Penetration, permeation, and resorption of 8-methoxypsoralen. Comperative in vitro and in vivo studies after topical application of four standard preparations.

PubMed

Kammerau, B; Klebe, U; Zesch, A; Schaefer, H

1976-03-10

The penetration, permeation, and resorption of radioactively labelled 8-Methoxypsoralen was investigated in human skin. Siultaneously, the effects to time and ointment carrier on the penetration kinetics were ascertained. The carriers tested were: vaseline, aqueous wool-wax alcohol ointment, aqueous hydrophilic ointment and polyethylene glycol ointment. The absolute concentrations of 8-Methoxypsoralen were estimated in the horny layer, epidermis and dermis. With the most advantageous carrier, aqueous wool-wax alcohol ointment, 4-6X10(-5) M and 10(-5) M were attained in the epidermis and dermis, respectively. Moreover, it was shown that the substance penetrates rapidly (10 min) into the epidermis and dermis and the high concentrations reached constant over a period of 16 h. Only with a formulation of aqueous wool-wax alcohols is any accumulation at all achieved in the deeper areas of the horny layer. A uniform decrease in drug concentration with increasing depth of the horny layer is found with the other 3 vehicles, whereby slight variations in concentrations pertain from carrier to carrier. 4 h after local application, 8-Methoxypsoralen can be detected in the urine. Regardless of the ointment base employed, 8-Methoxypsoralen is no longer detectable in the urine 40 h after application. In comparison to the oral therapy, the same magnitude of percutaneous resorption into the central compartment is to be derived from the data, if half the body surface is treated locally.

In vitro protective effect of a Jacquez grapes wine extract on UVB-induced skin damage.

PubMed

Tomaino, A; Cristani, M; Cimino, F; Speciale, A; Trombetta, D; Bonina, F; Saija, A

2006-12-01

Several studies have shown that UV radiation on the skin results in the formation of reactive oxygen species (ROS) that interact with proteins, lipids and DNA, thus altering cellular functions. The epidermis is composed mainly of keratinocytes, rich in ROS detoxifying enzymes and in low-molecular-mass antioxidant molecules. However, the increased generation of ROS can overwhelm the natural defences against oxidative stress. Therefore treatment of the skin with products containing plant-derived antioxidant ingredients may be a useful strategy for the prevention of UV-mediated cutaneous damage. In the present study we have investigated the in vitro capability of a Jacquez grapes wine extract (containing a significant level of proanthocyanidins, together with lower amounts of anthocyanins and hydroxycinnamic acids; JW-E), to protect skin against UVB-induced oxidative damage by using a three-dimensional tissue culture model of human epidermis. The endpoints of our experiments were cell viability, release of interleukin-1alpha and prostaglandin E(2) (well-known mediators of cutaneous inflammatory processes), accumulation in the epidermis of malondialdehyde/4-hydroxynonenal and protein carbonyl groups (derived by the oxidative damage respectively of lipids and proteins) and tissue redox balance (expressed by the levels of reduced glutathione, oxidized glutathione, glutathione peroxidase and glutathione reductase). Taken together, our findings demonstrate that the JW-E is an efficient botanical mixture able to prevent skin oxidative damage induced by UV-B exposure and may thus be a potential promising candidate as a skin photoprotective agent.

An analysis of heat removal during cryogen spray cooling and effects of simultaneous airflow application.

PubMed

Torres, J H; Tunnell, J W; Pikkula, B M; Anvari, B

2001-01-01

Cryogen spray cooling (CSC) is a method used to protect the epidermis from non-specific thermal injury that may occur as a result of various dermatological laser procedures. However, better understanding of cryogen deposition and skin thermal response to CSC is needed to optimize the technique. Temperature measurements and video imaging were carried out on an epoxy phantom as well as human skin during CSC with and without simultaneous application of airflow which was intended to accelerate cryogen evaporation from the substrate surface. An inverse thermal conduction model was used to estimate heat flux and total heat removed. Lifetime of the cryogen film deposited on the surface of skin and epoxy phantom lasted several hundred milliseconds beyond the spurt, but could be reduced to the spurt duration by application of airflow. Values over 100 J/cm(3) were estimated for volumetric heat removed from the epidermis using CSC. "Film cooling" instead of "evaporative cooling" appears to be the dominant mode of CSC on skin. Estimated values of heat removed from the epidermis suggest that a cryogen spurt as long as 200 milliseconds is required to counteract heat generated by high laser fluences (e.g., in treatment of port wine stains) in patients with high concentration of epidermal melanin. Additional cooling beyond spurt termination can be avoided by simultaneous application of airflow, although it is unclear at the moment if avoiding the additional cooling would be beneficial in the actual clinical situation. Copyright 2001 Wiley-Liss, Inc.

The effects of esterified solvents on the diffusion of a model compound across human skin: an ATR-FTIR spectroscopic study.

PubMed

McAuley, W J; Chavda-Sitaram, S; Mader, K T; Tetteh, J; Lane, M E; Hadgraft, J

2013-04-15

Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy has been used to investigate the effects of three fatty acid esters on skin permeation. Propylene glycol diperlargonate (DPPG), isopropyl myristate (IPM) and isostearyl isostearate (ISIS) were selected as pharmaceutically relevant solvents with a range of lipophilicities and cyanophenol (CNP) was used as a model drug. The resultant data were compared with that obtained when water was used as the solvent. The diffusion of CNP, DPPG and IPM across epidermis was successfully described by a Fickian model. When ISIS was used as a solvent Fickian behaviour was only obtained across isolated stratum corneum suggesting that the hydrophilic layers of the epidermis interfere with the permeation of the hydrophobic ISIS. The diffusion coefficients of CNP across epidermis in the different solvents were not significantly different. Using chemometric data analysis diffusion profiles for the solvents were deconvoluted from that of the skin and modelled. Each of these solvents was found to diffuse at a faster rate across the skin than CNP. DPPG considerably increased the concentration of CNP in the stratum corneum in comparison with the other solvents indicating strong penetration enhancer potential. In contrast IPM produced a similar CNP concentration in the stratum corneum to water with ISIS resulting in a lower CNP concentration suggesting negligible enhancement and penetration retardation effects for these two solvents respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

Immunocytochemical and autoradiographic studies on the process of keratinization in avian epidermis suggests absence of keratohyalin.

PubMed

Alibardi, Lorenzo

2004-02-01

The process of keratinization in apteric avian epidermis and in scutate scales of some avian species has been studied by autoradiography for histidine and immunohistochemistry for keratins and other epidermal proteins. Acidic or basic alpha-keratins are present in basal, spinosus, and transitional layers, but are not seen in the corneous layer. Keratinization-specific alpha-keratins (AE2-positive) are observed in the corneous layer of apteric epidermis but not in that of scutate scales, which contain mainly beta-keratin. Alpha-keratin bundles accumulate along the plasma membrane of transitional cells of apteric epidermis. In contrast to the situation in scutate scales, in the transitional layer and in the lowermost part of the corneous layer of apteric epidermis, filaggrin-like, loricrin-like, and transglutaminase immunoreactivities are present. The lack of isopeptide bond immunoreactivity suggests that undetectable isopeptide bonds are present in avian keratinocytes. Using immunogold ultrastructural immunocytochemistry a low but localized loricrin-like and, less, filaggrin-like labeling is seen over round-oval granules or vesicles among keratin bundles of upper spinosus and transitional keratinocytes of apteric epidermis. Filaggrin-and loricrin-labeling are absent in alpha-keratin bundles localized along the plasma membrane and in the corneous layer, formerly considered keratohyalin. Using ultrastructural autoradiography for tritiated histidine, occasional trace grains are seen among these alpha-keratin bundles. A different mechanism of redistribution of matrix and corneous cell envelope proteins probably operates in avian keratinocytes as compared to that of mammals. Keratin bundles are compacted around the lipid-core of apteric epidermis keratinocytes, which do not form complex chemico/mechanical-resistant corneous cell envelopes as in mammalian keratinocytes. These observations suggest that low amounts of matrix proteins are present among keratin bundles of avian keratinocytes and that keratohyalin granules are absent. Copyright 2003 Wiley-Liss, Inc.

Synthesis of Very-Long-Chain Fatty Acids in the Epidermis Controls Plant Organ Growth by Restricting Cell Proliferation

PubMed Central

Nobusawa, Takashi; Okushima, Yoko; Nagata, Noriko; Kojima, Mikiko; Sakakibara, Hitoshi; Umeda, Masaaki

2013-01-01

Plant organ growth is controlled by inter-cell-layer communication, which thus determines the overall size of the organism. The epidermal layer interfaces with the environment and participates in both driving and restricting growth via inter-cell-layer communication. However, it remains unknown whether the epidermis can send signals to internal tissue to limit cell proliferation in determinate growth. Very-long-chain fatty acids (VLCFAs) are synthesized in the epidermis and used in the formation of cuticular wax. Here we found that VLCFA synthesis in the epidermis is essential for proper development of Arabidopsis thaliana. Wild-type plants treated with a VLCFA synthesis inhibitor and pasticcino mutants with defects in VLCFA synthesis exhibited overproliferation of cells in the vasculature or in the rib zone of shoot apices. The decrease of VLCFA content increased the expression of IPT3, a key determinant of cytokinin biosynthesis in the vasculature, and, indeed, elevated cytokinin levels. These phenotypes were suppressed in ipt3;5;7 triple mutants, and also by vasculature-specific expression of cytokinin oxidase, which degrades active forms of cytokinin. Our results imply that VLCFA synthesis in the epidermis is required to suppress cytokinin biosynthesis in the vasculature, thus fine-tuning cell division activity in internal tissue, and therefore that shoot growth is controlled by the interaction between the surface (epidermis) and the axis (vasculature) of the plant body. PMID:23585732

Estrogen modulates mesenchyme-epidermis interactions in the adult nipple

PubMed Central

Wu, Hsing-Jung; Oh, Ji Won; Spandau, Dan F.; Tholpady, Sunil; Diaz, Jesus; Schroeder, Laura J.; Offutt, Carlos D.; Glick, Adam B.; Plikus, Maksim V.; Koyama, Sachiko

2017-01-01

Maintenance of specialized epidermis requires signals from the underlying mesenchyme; however, the specific pathways involved remain to be identified. By recombining cells from the ventral skin of the K14-PTHrP transgenic mice [which overexpress parathyroid hormone-related protein (PTHrP) in their developing epidermis and mammary glands] with those from wild type, we show that transgenic stroma is sufficient to reprogram wild-type keratinocytes into nipple-like epidermis. To identify candidate nipple-specific signaling factors, we compared gene expression signatures of sorted Pdgfrα-positive ventral K14-PTHrP and wild-type fibroblasts, identifying differentially expressed transcripts that are involved in WNT, HGF, TGFβ, IGF, BMP, FGF and estrogen signaling. Considering that some of the growth factor pathways are targets for estrogen regulation, we examined the upstream role of this hormone in maintaining the nipple. Ablation of estrogen signaling through ovariectomy produced nipples with abnormally thin epidermis, and we identified TGFβ as a negatively regulated target of estrogen signaling. Estrogen treatment represses Tgfβ1 at the transcript and protein levels in K14-PTHrP fibroblasts in vitro, while ovariectomy increases Tgfb1 levels in K14-PTHrP ventral skin. Moreover, ectopic delivery of Tgfβ1 protein into nipple connective tissue reduced epidermal proliferation. Taken together, these results show that specialized nipple epidermis is maintained by estrogen-induced repression of TGFβ signaling in the local fibroblasts. PMID:28289136

Morphology of the Epidermis of the Neotropical Catfish Pimelodella lateristriga (Lichtenstein, 1823) with Emphasis in Club Cells

PubMed Central

Damasceno, Eduardo Medeiros; Monteiro, Juliana Castro; Duboc, Luiz Fernando; Dolder, Heidi; Mancini, Karina

2012-01-01

The epidermis of Ostariophysi fish is composed of 4 main cell types: epidermal cells (or filament containing cells), mucous cells, granular cells and club cells. The morphological analysis of the epidermis of the catfish Pimelodella lateristriga revealed the presence of only two types of cells: epidermal and club cells. The latter were evident in the middle layer of the epidermis, being the largest cells within the epithelium. Few organelles were located in the perinuclear region, while the rest of the cytoplasm was filled with a non-vesicular fibrillar substance. Club cells contained two irregular nuclei with evident nucleoli and high compacted peripheral chromatin. Histochemical analysis detected prevalence of protein within the cytoplasm other than carbohydrates, which were absent. These characteristics are similar to those described to most Ostariophysi studied so far. On the other hand, the epidermal cells differ from what is found in the literature. The present study described three distinct types, as follows: superficial, abundant and dense cells. Differences among them were restricted to their cytoplasm and nucleus morphology. Mucous cells were found in all Ostariophysi studied so far, although they were absent in P. lateristriga, along with granular cells, also typical of other catfish epidermis. The preset study corroborates the observations on club cells' morphology in Siluriformes specimens, and shows important differences in epidermis composition and cell structure of P. lateristriga regarding the literature data. PMID:23226253

Alpha- and beta-keratins of the snake epidermis.

PubMed

Toni, Mattia; Alibardi, Lorenzo

2007-01-01

Snake scales contain specialized hard keratins (beta-keratins) and alpha- or cyto-keratins in their epidermis. The number, isoelectric point, and the evolution of these proteins in snakes and their similarity with those of other vertebrates are not known. In the present study, alpha- and beta-keratins of snake molts and of the whole epidermis have been studied by using two-dimensional electrophoresis and immunocytochemistry. Specific keratins in snake epidermis have been identified by using antibodies that recognize acidic and basic cytokeratins and avian or lizard scale beta-keratin. Alpha keratins of 40-70 kDa and isoelectric point (pI) at 4.5-7.0 are present in molts. The study suggests that cytokeratins in snakes are acidic or neutral, in contrast to mammals and birds where basic keratins are also present. Beta keratins of 10-15 kDa and a pI of 6.5-8.5 are found in molts. Some beta-keratins appear as basic proteins (pI 8.2) comparable to those present in the epidermis of other reptiles. Some basic "beta-keratins" associate with cytokeratins as matrix proteins and replace cytokeratins forming the corneous material of the mature beta-layer of snake scales, as in other reptiles. The study also suggests that more forms of beta-keratins (more than three different types) are present in the epidermis of snakes.

Assessment of cosmetic ingredients in the in vitro reconstructed human epidermis test method EpiSkin™ using HPLC/UPLC-spectrophotometry in the MTT-reduction assay.

PubMed

Alépée, N; Hibatallah, J; Klaric, M; Mewes, K R; Pfannenbecker, U; McNamee, P

2016-06-01

Cosmetics Europe recently established HPLC/UPLC-spectrophotometry as a suitable alternative endpoint detection system for measurement of formazan in the MTT-reduction assay of reconstructed human tissue test methods irrespective of the test system involved. This addressed a known limitation for such test methods that use optical density for measurement of formazan and may be incompatible for evaluation of strong MTT reducer and/or coloured chemicals. To build on the original project, Cosmetics Europe has undertaken a second study that focuses on evaluation of chemicals with functionalities relevant to cosmetic products. Such chemicals were primarily identified from the Scientific Committee on Consumer Safety (SCCS) 2010 memorandum (addendum) on the in vitro test EpiSkin™ for skin irritation testing. Fifty test items were evaluated in which both standard photometry and HPLC/UPLC-spectrophotometry were used for endpoint detection. The results obtained in this study: 1) provide further support for Within Laboratory Reproducibility of HPLC-UPLC-spectrophotometry for measurement of formazan; 2) demonstrate, through use a case study with Basazol C Blue pr. 8056, that HPLC/UPLC-spectrophotometry enables determination of an in vitro classification even when this is not possible using standard photometry and 3) addresses the question raised by SCCS in their 2010 memorandum (addendum) to consider an endpoint detection system not involving optical density quantification in in vitro reconstructed human epidermis skin irritation test methods. Copyright © 2016 Elsevier Ltd. All rights reserved.

A custom tailored model to investigate skin penetration in porcine skin and its comparison with human skin.

PubMed

Herbig, Michael E; Houdek, Pia; Gorissen, Sascha; Zorn-Kruppa, Michaela; Wladykowski, Ewa; Volksdorf, Thomas; Grzybowski, Stephan; Kolios, Georgios; Willers, Christoph; Mallwitz, Henning; Moll, Ingrid; Brandner, Johanna M

2015-09-01

Reliable models for the determination of skin penetration and permeation are important for the development of new drugs and formulations. The intention of our study was to develop a skin penetration model which (1) is viable and well supplied with nutrients during the period of the experiment (2) is mimicking human skin as far as possible, but still is independent from the problems of supply and heterogeneity, (3) can give information about the penetration into different compartments of the skin and (4) considers specific inter-individual differences in skin thickness. In addition, it should be quick and inexpensive (5) and without ethical implications (6). Using a chemically divers set of four topically approved active pharmaceutical ingredients (APIs), namely diclofenac, metronidazole, tazarotene, and terbinafine, we demonstrated that the model allows reliable determination of drug concentrations in different layers of the viable epidermis and dermis. For APIs susceptible for skin metabolism, the extent of metabolic transformation in epidermis and dermis can be monitored. Furthermore, a high degree of accordance in the ability for discrimination of skin concentrations of the substances in different layers was found in models derived from porcine and human skin. Viability, proliferation, differentiation and markers for skin barrier function were surveyed in the model. This model, which we call 'Hamburg model of skin penetration' is particularly suited to support a rational ranking and selection of dermatological formulations within drug development projects. Copyright © 2015 Elsevier B.V. All rights reserved.

Terminal-group oxidation of retinol by mouse epidermis. Inhibition in vitro and in vivo.

PubMed Central

Connor, M J; Smit, M H

1987-01-01

Locally applied retinol is metabolized to retinoic acid in mouse epidermis in vivo. To characterize the oxidation system we investigated the ability of soluble extracts of hairless-mouse epidermis to convert retinol and retinal into retinoic acid. The extracts oxidized retinol to retinoic acid in two steps catalysed by two NAD+-dependent enzymes that were resolved on h.p.l.c. The first enzyme catalyses the reversible oxidation of retinol to retinal and is an alcohol dehydrogenase isoenzyme. The second enzyme oxidizes retinal to retinoic acid. Retinol oxidation by epidermal extracts was inhibited by the alcohol dehydrogenase inhibitor 4-methylpyrazole and by the polyene citral. The toxicity and relatively low potency at inhibiting the epidermal alcohol dehydrogenase isoenzyme curtailed the use of 4-methylpyrazole in vivo. However, citral significantly inhibited retinoic acid formation from retinol in the epidermis in vivo. The ability to inhibit the oxidation of retinol to retinoic acid in mouse epidermis provides a potential method to resolve the roles of retinol and retinoic acid in epithelial function. PMID:3663136

Leaf Epidermis of the Rheophyte Dyckia brevifolia Baker (Bromeliaceae)

PubMed Central

Lobo, Ghislaine Maria; de Souza, Thaysi Ventura; Voltolini, Caroline Heinig; Reis, Ademir

2013-01-01

Some species of Dyckia Schult. f., including Dyckia brevifolia Baker, are rheophytes that live in the fast-moving water currents of streams and rivers which are subject to frequent flooding, but also period of low water. This study aimed to analyze the leaf epidermis of D. brevifolia in the context of epidermal adaptation to this aquatic plant's rheophytic habitat. The epidermis is uniseriate, and the cuticle is thickened. The inner periclinal and anticlinal walls of the epidermal cells are thickened and lignified. Stomata are tetracytic, located in the depressions in relation to the surrounding epidermal cells, and covered by peltate trichomes. While the epidermal characteristics of D. brevifolia are similar to those of Bromeliaceae species, this species has made particular adaptations of leaf epidermis in response to its rheophytic environment. PMID:23864825

Differential susceptibility of primary cultured human skin cells to hypericin PDT in an in vitro model.

PubMed

Popovic, A; Wiggins, T; Davids, L M

2015-08-01

Skin cancer is the most common cancer worldwide, and its incidence rate in South Africa is increasing. Photodynamic therapy (PDT) has been shown to be an effective treatment modality, through topical administration, for treatment of non-melanoma skin cancers. Our group investigates hypericin-induced PDT (HYP-PDT) for the treatment of both non-melanoma and melanoma skin cancers. However, a prerequisite for effective cancer treatments is efficient and selective targeting of the tumoral cells with minimal collateral damage to the surrounding normal cells, as it is well established that cancer therapies have bystander effects on normal cells in the body, often causing undesirable side effects. The aim of this study was to investigate the cellular and molecular effects of HYP-PDT on normal primary human keratinocytes (Kc), melanocytes (Mc) and fibroblasts (Fb) in an in vitro tissue culture model which represented both the epidermal and dermal cellular compartments of human skin. Cell viability analysis revealed a differential cytotoxic response to a range of HYP-PDT doses in all the human skin cell types, showing that Fb (LD50=1.75μM) were the most susceptible to HYP-PDT, followed by Mc (LD50=3.5μM) and Kc (LD50>4μM HYP-PDT) These results correlated with the morphological analysis which displayed distinct morphological changes in Fb and Mc, 24h post treatment with non-lethal (1μM) and lethal (3μM) doses of HYP-PDT, but the highest HYP-PDT doses had no effect on Kc morphology. Fluorescent microscopy displayed cytoplasmic localization of HYP in all the 3 skin cell types and additionally, HYP was excluded from the nuclei in all the cell types. Intracellular ROS levels measured in Fb at 3μM HYP-PDT, displayed a significant 3.8 fold (p<0.05) increase in ROS, but no significant difference in ROS levels occurred in Mc or Kc. Furthermore, 64% (p<0.005) early apoptotic Fb and 20% (p<0.05) early apoptotic Mc were evident; using fluorescence activated cell sorting (FACS), 24h post 3μM HYP-PDT. These results depict a differential response to HYP-PDT by different human skin cells thus highlighting the efficacy and indeed, the potential bystander effect of if administered in vivo. This study contributes toward our knowledge of the cellular response of the epidermis to photodynamic therapies and will possibly enhance the efficacy of future photobiological treatments. Copyright © 2015 Elsevier B.V. All rights reserved.

Unusual presentation of generalized macular amyloidosis in a young adult.

PubMed

Kudur, Mohan H; Sathish, Pai B; Sripathi, H; Prabhu, Smitha

2008-01-01

Macular amyloidosis is a common problem seen dermatology out-patient department. Generalized macular amyloidosis presenting with a poikilodermatous appearance is rare. In our case, an 18-year-old male presented with generalized hypopigmented macules with a poikilodermatous appearance of 10-year duration. His developmental milestones were normal with negative family history of similar complaints. Histopathology of hyperpigmented lesions revealed hyperkeratosis and acanthosis of epidermis and hypopigmented lesion showing only hyperkeratosis. Both lesions were showing the deposition of amorphous, hazy material in the tips of papillary dermis with perivascular inflammatory infiltrate. Congo red staining of the amorphous material was positive for amyloid.

Molluscum Contagiosum Involving an Epidermoid Cyst - A Rare Association and Potential Source of Clinical Misdiagnosis.

PubMed

Ghosh, Prithwijit; Saha, Kaushik

2014-01-01

Molluscum contagiosum (MC) is a viral infection of skin and mucous membrane commonly affecting the adolescents and young adults. Extensive lesions are usually common in immunocompromised patients. We herein report a rare case of molluscum contagiosum in an epidermoid cyst (EC) in a 24-year-old immunocompetent male. The provisional clinical diagnosis was inflammed epidermoid cyst or lipoma. On histopathological examination, the lesion displayed a unilocular epidermoid cyst in deep dermis, the lining of which was infected by molluscum contagiosum virus with characteristic inclusions. The overlying epidermis was absolutely normal having no attachment with the cyst.

Various members of the Toll-like receptor family contribute to the innate immune response of human epidermal keratinocytes

PubMed Central

Köllisch, Gabriele; Kalali, Behnam Naderi; Voelcker, Verena; Wallich, Reinhard; Behrendt, Heidrun; Ring, Johannes; Bauer, Stefan; Jakob, Thilo; Mempel, Martin; Ollert, Markus

2005-01-01

Toll-like receptors (TLRs) are important pattern recognition molecules that activate the nuclear factor (NF)-κB pathway leading to the production of antimicrobial immune mediators. As keratinocytes represent the first barrier against exogenous pathogens in human skin, we investigated their complete functional TLR1–10 expression profile. First, reverse transcription–polymerase chain reaction (PCR) analysis revealed a very similar pattern of TLR mRNA expression when comparing freshly isolated human epidermis and cultured primary human keratinocytes. Thus, further experiments were carried out with primary keratinocytes in comparison with the spontaneously immortalized human keratinocyte cell line HaCaT. The quantitative expression of TLR1–10 mRNA in real-time PCR of primary human keratinocytes and HaCaT cells was analysed. Both cell types constitutively expressed TLR2, TLR3, TLR5, and to a lesser extent TLR10. TLR4 was only found in HaCaT cells, TLR1 to a higher degree in primary keratinocytes. In line with this, LPS induced mRNA expression of CD14 and TLR4 only in HaCaT cells. After stimulation with various TLR ligands, the NF-κB-activated chemokine interleukin-8 (IL-8) was measured. In primary keratinocytes and HaCaT cells the TLR3 ligand poly (I:C) was the most potent stimulator of IL-8 secretion. The TLR ligands peptidoglycan, Pam3Cys and flagellin which bind to TLR2, TLR1/TLR2 heterodimer, and TLR5, respectively, also induced IL-8 secretion, whereas no IL-8 was induced by LPS, R-848, loxoribine and cytosine guanine dinucleotide-containing oligodeoxynucleotide. A corresponding pattern was found in the RelA NF-κB translocation assay after ligand stimulation of primary keratinocytes. These studies provide substantial evidence for a functional TLR expression and signalling profile of normal human keratinocytes contributing to the antimicrobial defence barrier of human skin. PMID:15804290

Ontogeny and function of murine epidermal Langerhans cells.

PubMed

Kaplan, Daniel H

2017-09-19

Langerhans cells (LCs) are epidermis-resident antigen-presenting cells that share a common ontogeny with macrophages but function as dendritic cells (DCs). Their development, recruitment and retention in the epidermis is orchestrated by interactions with keratinocytes through multiple mechanisms. LC and dermal DC subsets often show functional redundancy, but LCs are required for specific types of adaptive immune responses when antigen is concentrated in the epidermis. This Review will focus on those developmental and functional properties that are unique to LCs.

Identification of a Novel Proto-oncogenic Network in Head and Neck Squamous Cell Carcinoma.

PubMed

Georgy, Smitha R; Cangkrama, Michael; Srivastava, Seema; Partridge, Darren; Auden, Alana; Dworkin, Sebastian; McLean, Catriona A; Jane, Stephen M; Darido, Charbel

2015-09-01

The developmental transcription factor Grainyhead-like 3 (GRHL3) plays a critical tumor suppressor role in the mammalian epidermis through direct regulation of PTEN and the PI3K/AKT/mTOR signaling pathway. GRHL3 is highly expressed in all tissues derived from the surface ectoderm, including the oral cavity, raising a question about its potential role in suppression of head and neck squamous cell carcinoma (HNSCC). We explored the tumor suppressor role of Grhl3 in HNSCC using a conditional knockout (Grhl3 (∆/-) /K14Cre (+) ) mouse line (n = 26) exposed to an oral chemical carcinogen. We defined the proto-oncogenic pathway activated in the HNSCC derived from these mice and assessed it in primary human HNSCC samples, normal oral epithelial cell lines carrying shRNA to GRHL3, and human HNSCC cell lines. Data were analyzed with two-sided chi square and Student's t tests. Deletion of Grhl3 in oral epithelium in mice did not perturb PTEN/PI3K/AKT/mTOR signaling, but instead evoked loss of GSK3B expression, resulting in stabilization and accumulation of c-MYC and aggressive HNSCC. This molecular signature was also evident in a subset of primary human HNSCC and HNSCC cell lines. Loss of Gsk3b in mice, independent of Grhl3, predisposed to chemical-induced HNSCC. Restoration of GSK3B expression blocked proliferation of normal oral epithelial cell lines carrying shRNA to GRHL3 (cell no., Day 8: Scramble ctl, 616±21.8 x 10(3) vs GRHL3-kd, 1194±44 X 10(3), P < .001; GRHL3-kd vs GRHL3-kd + GSK3B, 800±98.84 X 10(3), P = .003) and human HNSCC cells. We defined a novel molecular signature in mammalian HNSCC, suggesting new treatment strategies targeting the GRHL3/GSK3B/c-MYC proto-oncogenic network. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Aberrant upregulation of MUC4 mucin expression in cutaneous condyloma acuminatum and squamous cell carcinoma suggests a potential role in the diagnosis and therapy of skin diseases.

PubMed

Chakraborty, Subhankar; Swanson, Benjamin J; Bonthu, Neelima; Batra, Surinder K

2010-07-01

Mucins comprise a family of high-molecular-weight glycoproteins. MUC4, a large transmembrane mucin, has recently emerged as a novel marker for diagnosis, prognosis and therapy in several malignancies. However, its role in skin pathologies remains unknown. The aim of this study was to analyse the expression of MUC4 in cutaneous pathologies by immunohistochemistry for potential diagnostic, prognostic and therapeutic applications. A total of 330 tissue spots representing the normal skin, and benign and malignant cutaneous diseases, were analysed after staining with the monoclonal antibody to human MUC4 (clone 8G7). While the normal epidermis showed a negative to weak-positive expression of MUC4, its expression was significantly upregulated in squamous cell carcinomas (SCCs) where the intensity of staining correlated negatively with tumour grade and positively with age. A moderately strong MUC4 expression was also noted in 2/20 cancer adjacent normal skin and 2/21 chronically inflamed skin tissues, while 10/19 cases of vulval condyloma acuminate, 3/12 of vulval hyperplasia and 2 cases of verruca vulgaris also showed strong MUC4 positivity. Malignant melanoma, basal cell carcinoma and cutaneous cysts were negative. The results indicate that MUC4 expression is aberrantly upregulated in cutaneous SCCs, vulval condylomas and verruca vulgaris. Further, it appears that MUC4 expression in the skin may be modulated by chronic inflammation and the presence of an adjacent cutaneous malignancy in certain cases. These observations suggest a novel role for MUC4 mucin in the pathogenesis of cutaneous SCC and a possible application as a diagnostic and/or prognostic marker in cutaneous pathologies.

[Normal and abnormal skin color].

PubMed

Ortonne, J-P

2012-11-01

The varieties of normal skin color in humans range from people of "no color" (pale white) to "people of color" (light brown, dark brown, and black). Skin color is a blend resulting from the skin chromophores red (oxyhaemoglobin), blue (deoxygenated haemoglobin), yellow-orange (carotene, an exogenous pigment), and brown (melanin). Melanin, however, is the major component of skin color ; it is the presence or absence of melanin in the melanosomes in melanocytes and melanin in keratinocytes that is responsible for epidermal pigmentation, and the presence of melanin in macrophages or melanocytes in the dermis that is responsible for dermal pigmentation. Two groups of pigmentary disorders are commonly distinguished: the disorders of the quantitative and qualitative distribution of normal pigment and the abnormal presence of exogenous or endogenous pigments in the skin. The first group includes hyperpigmentations, which clinically manifest by darkening of the skin color, and leukodermia, which is characterized by lightening of the skin. Hypermelanosis corresponds to an overload of melanin or an abnormal distribution of melanin in the skin. Depending on the color, melanodermia (brown/black) and ceruloderma (blue/grey) are distinguished. Melanodermia correspond to epidermal hypermelanocytosis (an increased number of melanocytes) or epidermal hypermelanosis (an increase in the quantity of melanin in the epidermis with no modification of the number of melanocytes). Ceruloderma correspond to dermal hypermelanocytosis (abnormal presence in the dermis of cells synthesizing melanins) ; leakage in the dermis of epidermal melanin also exists, a form of dermal hypermelanosis called pigmentary incontinence. Finally, dyschromia can be related to the abnormal presence in the skin of a pigment of exogenous or endogenous origin. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Shining a Light on Black Holes in Keratinocytes.

PubMed

Bowman, Shanna L; Marks, Michael S

2018-03-01

The mechanisms by which melanins are transferred from melanocytes and stored within keratinocytes to generate skin pigmentation are hotly debated. Correia et al. and Hurbain et al. provide evidence that melanin cores of melanosomes are secreted from melanocytes and taken up and stored within non-degradative membranous organelles in keratinocytes in the basal epidermis of human skin. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Automatic evaluation of skin histopathological images for melanocytic features

NASA Astrophysics Data System (ADS)

Koosha, Mohaddeseh; Hoseini Alinodehi, S. Pourya; Nicolescu, Mircea; Safaei Naraghi, Zahra

2017-03-01

Successfully detecting melanocyte cells in the skin epidermis has great significance in skin histopathology. Because of the existence of cells with similar appearance to melanocytes in hematoxylin and eosin (HE) images of the epidermis, detecting melanocytes becomes a challenging task. This paper proposes a novel technique for the detection of melanocytes in HE images of the epidermis, based on the melanocyte color features, in the HSI color domain. Initially, an effective soft morphological filter is applied to the HE images in the HSI color domain to remove noise. Then a novel threshold-based technique is applied to distinguish the candidate melanocytes' nuclei. Similarly, the method is applied to find the candidate surrounding halos of the melanocytes. The candidate nuclei are associated with their surrounding halos using the suggested logical and statistical inferences. Finally, a fuzzy inference system is proposed, based on the HSI color information of a typical melanocyte in the epidermis, to calculate the similarity ratio of each candidate cell to a melanocyte. As our review on the literature shows, this is the first method evaluating epidermis cells for melanocyte similarity ratio. Experimental results on various images with different zooming factors show that the proposed method improves the results of previous works.

A rapid, highly efficient and economical method of Agrobacterium-mediated in planta transient transformation in living onion epidermis.

PubMed

Xu, Kedong; Huang, Xiaohui; Wu, Manman; Wang, Yan; Chang, Yunxia; Liu, Kun; Zhang, Ju; Zhang, Yi; Zhang, Fuli; Yi, Liming; Li, Tingting; Wang, Ruiyue; Tan, Guangxuan; Li, Chengwei

2014-01-01

Transient transformation is simpler, more efficient and economical in analyzing protein subcellular localization than stable transformation. Fluorescent fusion proteins were often used in transient transformation to follow the in vivo behavior of proteins. Onion epidermis, which has large, living and transparent cells in a monolayer, is suitable to visualize fluorescent fusion proteins. The often used transient transformation methods included particle bombardment, protoplast transfection and Agrobacterium-mediated transformation. Particle bombardment in onion epidermis was successfully established, however, it was expensive, biolistic equipment dependent and with low transformation efficiency. We developed a highly efficient in planta transient transformation method in onion epidermis by using a special agroinfiltration method, which could be fulfilled within 5 days from the pretreatment of onion bulb to the best time-point for analyzing gene expression. The transformation conditions were optimized to achieve 43.87% transformation efficiency in living onion epidermis. The developed method has advantages in cost, time-consuming, equipment dependency and transformation efficiency in contrast with those methods of particle bombardment in onion epidermal cells, protoplast transfection and Agrobacterium-mediated transient transformation in leaf epidermal cells of other plants. It will facilitate the analysis of protein subcellular localization on a large scale.

Antimicrobial peptides and pro-inflammatory cytokines are differentially regulated across epidermal layers following bacterial stimuli.

PubMed

Percoco, Giuseppe; Merle, Chloé; Jaouen, Thomas; Ramdani, Yasmina; Bénard, Magalie; Hillion, Mélanie; Mijouin, Lily; Lati, Elian; Feuilloley, Marc; Lefeuvre, Luc; Driouich, Azeddine; Follet-Gueye, Marie-Laure

2013-12-01

The skin is a natural barrier between the body and the environment and is colonised by a large number of microorganisms. Here, we report a complete analysis of the response of human skin explants to microbial stimuli. Using this ex vivo model, we analysed at both the gene and protein level the response of epidermal cells to Staphylococcus epidermidis (S. epidermidis) and Pseudomonas fluorescens (P. fluorescens), which are present in the cutaneous microbiota. We showed that both bacterial species affect the structure of skin explants without penetrating the living epidermis. We showed by real-time quantitative polymerase chain reaction (qPCR) that S. epidermidis and P. fluorescens increased the levels of transcripts that encode antimicrobial peptides (AMPs), including human β defensin (hBD)2 and hBD3, and the pro-inflammatory cytokines interleukin (IL)-1α and (IL)-1-β, as well as IL-6. In addition, we analysed the effects of bacterial stimuli on the expression profiles of genes related to innate immunity and the inflammatory response across the epidermal layers, using laser capture microdissection (LCM) coupled to qPCR. We showed that AMP transcripts were principally upregulated in suprabasal keratinocytes. Conversely, the expression of pro-inflammatory cytokines was upregulated in the lower epidermis. These findings were confirmed by protein localisation using specific antibodies coupled to optical or electron microscopy. This work underscores the potential value of further studies that use LCM on human skin explants model to study the roles and effects of the epidermal microbiota on human skin physiology. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Lipid functions in skin: Differential effects of n-3 polyunsaturated fatty acids on cutaneous ceramides, in a human skin organ culture model.

PubMed

Kendall, Alexandra C; Kiezel-Tsugunova, Magdalena; Brownbridge, Luke C; Harwood, John L; Nicolaou, Anna

2017-09-01

Ceramides are important for skin health, with a multitude of species found in both dermis and epidermis. The epidermis contains linoleic acid-Ester-linked Omega-hydroxylated ceramides of 6-Hydroxy-sphingosine, Sphingosine and Phytosphingosine bases (CER[EOH], CER[EOS] and CER[EOP], respectively), that are crucial for the formation of the epidermal barrier, conferring protection from environmental factors and preventing trans-epidermal water loss. Furthermore, a large number of ceramides, derivatives of the same sphingoid bases and various fatty acids, are produced by dermal and epidermal cells and perform signalling roles in cell functions ranging from differentiation to apoptosis. Supplementation with the n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have shown promise as therapeutic agents in a number of inflammatory skin conditions, altering the lipid profile of the skin and production of bioactive lipids such as the eicosanoids, docosanoids and endocannabinoids. In this study we wished to investigate whether EPA and DHA could also affect the ceramide profile in epidermis and dermis, and, in this way, contribute to formation of a robust lipid barrier and ceramide-mediated regulation of skin functions. Ex vivo skin explants were cultured for 6days, and supplemented with EPA or DHA (50μM). Liquid chromatography coupled to tandem mass spectrometry with electrospray ionisation was used to assess the prevalence of 321 individual ceramide species, and a number of sphingoid bases, phosphorylated sphingoid bases, and phosphorylated ceramides, within the dermis and epidermis. EPA augmented dermal production of members of the ceramide families containing Non-hydroxy fatty acids and Sphingosine or Dihydrosphingosine bases (CER[NS] and CER[NDS], respectively), while epidermal CER[EOH], CER[EOS] and CER[EOP] ceramides were not affected. DHA did not significantly affect ceramide production. Ceramide-1-phosphate levels in the epidermis, but not the dermis, increased in response to EPA, but not DHA. This ex vivo study shows that dietary supplementation with EPA has the potential to alter the ceramide profile of the skin, and this may contribute to its anti-inflammatory profile. This has implications for formation of the epidermal lipid barrier, and signalling pathways within the skin mediated by ceramides and other sphingolipid species. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Skn-1a/Oct-11 and {Delta}Np63{alpha} exert antagonizing effects on human keratin expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lena, Anna Maria; Cipollone, Rita; Amelio, Ivano

2010-10-29

Research highlights: {yields} Skn-1a markedly downregulates {Delta}Np63-driven K14 expression. {yields} {Delta}Np63 inhibits Skn-1a-mediated K10 expression. {yields} {Delta}Np63, mutated in SAM domain, is less effecting in K10 downregulation. {yields} Immunolocalization in human skin of the two transcription factors is partially overlapping. {yields} The antagonistic effects of Skn-1a and p63 is through competition for overlapping responsive elements or through an indirect interaction. -- Abstract: The formation of a stratified epidermis requires a carefully controlled balance between keratinocyte proliferation and differentiation. Here, we report the reciprocal effect on keratin expression of {Delta}Np63, pivotal in normal epidermal morphogenesis and maintenance, and Skn-1a/Oct-11, a POUmore » transcription factor that triggers and regulates the differentiation of keratinocytes. The expression of Skn-1a markedly downregulated {Delta}Np63-driven K14 expression in luciferase reporter assays. The extent of downregulation was comparable to the inhibition of Skn-1a-mediated K10 expression upon expression of {Delta}Np63. {Delta}Np63, mutated in the protein-protein interaction domain (SAM domain; mutated in human ectodermal dysplasia syndrome), was significantly less effecting in downregulating K10, raising the possibility of a direct interaction among Skn-1a and {Delta}Np63. Immunolocalization in human skin biopsies revealed that the expression of the two transcription factors is partially overlapping. Co-immunoprecipitation experiments did not, however, demonstrate a direct interaction between {Delta}Np63 and Skn-1a, suggesting that the antagonistic effects of Skn-1a and p63 on keratin promoter transactivation is probably through competition for overlapping binding sites on target gene promoter or through an indirect interaction.« less

TCDD induces dermal accumulation of keratinocyte-derived matrix metalloproteinase-10 in an organotypic model of human skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Abrew, K. Nadira; Thomas-Virnig, Christina L.; Rasmussen, Cathy A.

2014-05-01

The epidermis of skin is the first line of defense against the environment. A three dimensional model of human skin was used to investigate tissue-specific phenotypes induced by the environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Continuous treatment of organotypic cultures of human keratinocytes with TCDD resulted in intracellular spaces between keratinocytes of the basal and immediately suprabasal layers as well as thinning of the basement membrane, in addition to the previously reported hyperkeratinization. These tissue remodeling events were preceded temporally by changes in expression of the extracellular matrix degrading enzyme, matrix metalloproteinase-10 (MMP-10). In organotypic cultures MMP-10 mRNA and protein were highlymore » induced following TCDD treatment. Q-PCR and immunoblot results from TCDD-treated monolayer cultures, as well as indirect immunofluorescence and immunoblot analysis of TCDD-treated organotypic cultures, showed that MMP-10 was specifically contributed by the epidermal keratinocytes but not the dermal fibroblasts. Keratinocyte-derived MMP-10 protein accumulated over time in the dermal compartment of organotypic cultures. TCDD-induced epidermal phenotypes in organotypic cultures were attenuated by the keratinocyte-specific expression of tissue inhibitor of metalloproteinase-1, a known inhibitor of MMP-10. These studies suggest that MMP-10 and possibly other MMP-10-activated MMPs are responsible for the phenotypes exhibited in the basement membrane, the basal keratinocyte layer, and the cornified layer of TCDD-treated organotypic cultures. Our studies reveal a novel mechanism by which the epithelial–stromal microenvironment is altered in a tissue-specific manner thereby inducing structural and functional pathology in the interfollicular epidermis of human skin. - Highlights: • TCDD causes hyperkeratosis and basement membrane changes in a model of human skin. • TCDD induces MMP-10 expression in organotypic cultures of human keratinocytes. • Keratinocyte-expressed MMP-10 accumulates in the dermal compartment. • Keratinocyte K14 promoter-driven TIMP-1 expression ablates TCDD-induced phenotypes.« less

Confocal Raman spectroscopy: In vivo biochemical changes in the human skin by topical formulations under UV radiation.

PubMed

Tosato, M G; Orallo, D E; Ali, S M; Churio, M S; Martin, A A; Dicelio, L

2015-12-01

A new approach to the study of the effects on human skin of mycosporine-like amino acids (MAAs) and gadusol (Gad) incorporated in polymer gel is proposed in this work. The depth profile and photoprotector effects of Pluronic F127® gels containing each of the natural actives were evaluated by in vivo confocal Raman spectroscopy aiming at the analysis of the biochemical changes on human skin. Hierarchical cluster analysis (HCA) showed that the data corresponding to different depths of the skin, from surface to 4 μm, and from 6 to 16 μm, remained in the same cluster. In vivo Raman spectra, classified into five different layers of epidermis according to their similarities, indicated that the amount of Gad gel increased by about 26% in the outermost layer of the stratum corneum (SC) and that MAAs gel at 2 μm depth was 103.4% higher than in the outermost layer of the SC. Variations in the SC of urocanic acid at 1490-1515 cm(-1) and 1652 cm(-1) and histidine at 1318 cm(-1) were calculated, before and after UV exposure with or without gels. With the application of gels the vibrational modes that correspond to lipids in trans conformation (1063 and 1128 cm(-1)) increased with respect to normal skin, whereas gauche conformation (1085 cm(-1)) disappeared. Our studies suggest that gels protected the skin against the stress of the natural defense mechanism caused by high levels of UV exposure. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of Asparagus racemosus extract on transdermal delivery of carvedilol: a mechanistic study.

PubMed

Sapra, Bharti; Jain, Subheet; Tiwary, Ashok K

2009-01-01

This study was designed for investigating the effect of Asparagus racemosus (AR) extract and chitosan (CTN) in facilitating the permeation of carvedilol (CDL) across rat epidermis. Transdermal flux of carvedilol through heat-separated rat epidermis was investigated in vitro using vertical Keshary-Chien diffusion cells. Biophysical and microscopic manifestations of epidermis treated with AR extract, CTN, and AR extract-CTN mixture were investigated by using differential scanning calorimetry, transepidermal water loss, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Biochemical estimations of cholesterol, sphingosine, and triglycerides were carried out for treated excised as well as viable rat epidermis. The antihypertensive activity of the patches in comparison with that of oral carvedilol was studied in deoxycorticosterone acetate-induced hypertensive rats. The permeation of carvedilol across excised rat epidermis was significantly higher (p < 0.05) when AR extract, CTN, or AR extract-CTN mixture was used as donor vehicle as compared to propylene glycol/ethanol (7:3) mixture. Epidermis obtained after 12 h treatment of viable rat skin with AR extract-CTN mixture showed significantly higher (p < 0.05) permeability to CDL as compared to that after treatment with AR extract or CTN alone. Further, the application of patches containing AR extract-CTN mixture resulted in sustained release of CDL which was able to control the hypertension in deoxycorticosterone acetate-induced hypertensive rats through 36 h. Estimation of micro constituents in rat epidermis revealed maximum extraction of cholesterol, sphingosine, and triglycerides after treatment with AR extract-CTN mixture. This was manifested in altered lipid and protein-specific thermotropic transitions. Further, increase in intercellular space, disordered lipid structure, and corneocyte detachment as observed in SEM and TEM suggested great potential of AR extract for use as percutaneous permeation enhancer. The developed transdermal patches of CDL containing AR extract-CTN mixture exhibited better performance as compared to oral administration in controlling hypertension in rats.

Clonal evolution and progression of 20-methylcholanthrene-induced squamous cell carcinoma of mouse epidermis as revealed by DNA instability and other malignancy markers.

PubMed

Hirai, K; Kumakiri, M; Ueda, K; Imamura, Y; Noriki, S; Nishi, Y; Kato, H; Fukuda, M

2001-01-01

We examined the clonal evolution of skin malignant lesions by repeated topical applications of 20-methylcholanthrene (20-MC) to the skin, which induces hyperplastic epidermis, papillomatous lesion and invasive carcinoma in mice. The lesions were examined histologically and immunohistochemically with anti-single-stranded DNA after acid hydrolysis (DNA-instability test), p53, VEGF, DFF45, PCNA and AgNORs parameters analyses. Multiple clones with increased DNA instability comparable to that of invasive carcinoma were noted in early-stage (2-6 weeks) hyperplastic epidermis, and their number increased in middle (7-11 weeks), and late-stages (12-25 weeks) of hyperplastic epidermis, indicating that they belong to the malignancy category. All papillomatous lesions and invasive carcinomas showed a positive DNA-instability test. Positive immunostaining for various biomarkers and AgNORs parameters appeared in clones with a positive DNA-instability test in early-or middle-stage hyperplastic epidermis, and markedly increased in late-stage hyperplastic epidermis, papillomatous lesions and invasive carcinomas. The percentage of PCNA-positive vascular endothelial cells was significantly higher in VEGF-positive lesions with a positive DNA-instability test and became higher toward the late-stage of progression. Cut-woundings were made to papillomatous and invasive carcinoma lesions, and the regeneration activity of vascular endothelial cells was determined by using flash labeling with tritiated thymidine (3H-TdR). In small papillomatous lesions, vascular endothelial cells showed regenerative response, but the response was weak in large lesions. No such response was noted in invasive carcinomas; rather, cut-wounding induced collapse of blood vessels, which in turn induced massive coagulative necrosis of cancer cells. These responses can be interpreted to reflect exhausted vascular growth activity due to excessive stimulation by VEGF-overexpression, which was persistently seen from hyperplastic epidermis to invasive carcinoma.

β-Defensin-2 Protein Is a Serum Biomarker for Disease Activity in Psoriasis and Reaches Biologically Relevant Concentrations in Lesional Skin

PubMed Central

Jansen, Patrick A. M.; Rodijk-Olthuis, Diana; Hollox, Edward J.; Kamsteeg, Marijke; Tjabringa, Geuranne S.; de Jongh, Gys J.; van Vlijmen-Willems, Ivonne M. J. J.; Bergboer, Judith G. M.; van Rossum, Michelle M.; de Jong, Elke M. G. J.; den Heijer, Martin; Evers, Andrea W. M.; Bergers, Mieke; Armour, John A. L.

2009-01-01

Background Previous studies have extensively documented antimicrobial and chemotactic activities of beta-defensins. Human beta-defensin-2 (hBD-2) is strongly expressed in lesional psoriatic epidermis, and recently we have shown that high beta-defensin genomic copy number is associated with psoriasis susceptibility. It is not known, however, if biologically and pathophysiologically relevant concentrations of hBD-2 protein are present in vivo, which could support an antimicrobial and proinflammatory role of beta-defensins in lesional psoriatic epidermis. Methodology/Principal Findings We found that systemic levels of hBD-2 showed a weak but significant correlation with beta defensin copy number in healthy controls but not in psoriasis patients with active disease. In psoriasis patients but not in atopic dermatitis patients, we found high systemic hBD-2 levels that strongly correlated with disease activity as assessed by the PASI score. Our findings suggest that systemic levels in psoriasis are largely determined by secretion from involved skin and not by genomic copy number. Modelling of the in vivo epidermal hBD-2 concentration based on the secretion rate in a reconstructed skin model for psoriatic epidermis provides evidence that epidermal hBD-2 levels in vivo are probably well above the concentrations required for in vitro antimicrobial and chemokine-like effects. Conclusions/Significance Serum hBD-2 appears to be a useful surrogate marker for disease activity in psoriasis. The discrepancy between hBD-2 levels in psoriasis and atopic dermatitis could explain the well known differences in infection rate between these two diseases. PMID:19266104

The epidermis coordinates auxin-induced stem growth in response to shade

PubMed Central

Procko, Carl; Burko, Yogev; Long, Jeff A.; Chory, Joanne

2016-01-01

Growth of a complex multicellular organism requires coordinated changes in diverse cell types. These cellular changes generate organs of the correct size, shape, and functionality. In plants, the growth hormone auxin induces stem elongation in response to shade; however, which cell types of the stem perceive the auxin signal and contribute to organ growth is poorly understood. Here, we blocked the transcriptional response to auxin within specific tissues to show that auxin signaling is required in many cell types for correct hypocotyl growth in shade, with a key role for the epidermis. Combining genetic manipulations in Arabidopsis thaliana with transcriptional profiling of the hypocotyl epidermis from Brassica rapa, we show that auxin acts in the epidermis in part by inducing activity of the locally acting, growth-promoting brassinosteroid pathway. Our findings clarify cell-specific auxin function in the hypocotyl and highlight the complexity of cell type interactions within a growing organ. PMID:27401556

Mechanochemical Polarization of Contiguous Cell Walls Shapes Plant Pavement Cells.

PubMed

Majda, Mateusz; Grones, Peter; Sintorn, Ida-Maria; Vain, Thomas; Milani, Pascale; Krupinski, Pawel; Zagórska-Marek, Beata; Viotti, Corrado; Jönsson, Henrik; Mellerowicz, Ewa J; Hamant, Olivier; Robert, Stéphanie

2017-11-06

The epidermis of aerial plant organs is thought to be limiting for growth, because it acts as a continuous load-bearing layer, resisting tension. Leaf epidermis contains jigsaw puzzle piece-shaped pavement cells whose shape has been proposed to be a result of subcellular variations in expansion rate that induce local buckling events. Paradoxically, such local compressive buckling should not occur given the tensile stresses across the epidermis. Using computational modeling, we show that the simplest scenario to explain pavement cell shapes within an epidermis under tension must involve mechanical wall heterogeneities across and along the anticlinal pavement cell walls between adjacent cells. Combining genetics, atomic force microscopy, and immunolabeling, we demonstrate that contiguous cell walls indeed exhibit hybrid mechanochemical properties. Such biochemical wall heterogeneities precede wall bending. Altogether, this provides a possible mechanism for the generation of complex plant cell shapes. Copyright © 2017 Elsevier Inc. All rights reserved.

Glycophenotype evaluation in cutaneous tumors using lectins labeled with acridinium ester.

PubMed

Lima, Luiza Rayanna Amorim; Bezerra, Matheus Filgueira; Almeida, Sinara Mônica Vitalino; Silva, Lúcia Patrícia Bezerra Gomes; Beltrão, Eduardo Isidoro Carneiro; Carvalho Júnior, Luiz Bezerra

2013-01-01

Tumor cells show alterations in their glycosylation patterns when compared to normal cells. Lectins can be used to evaluate these glycocode changes. Chemiluminescence assay is an effective technique for quantitative analysis of proteins, nucleic acids, and carbohydrates due to its high sensitivity, specificity, and rapid testing. To use histochemiluminescence based on lectin conjugated to acridinium ester (AE) for the investigation of glycophenotype changes in cutaneous tumors. Concanavalin A (Con A), Peanut agglutinin (PNA), Ulex europaeus agglutinin-I (UEA-I), and Maackia amurensis agglutinin (MAA) were conjugated to acridinium ester. Biopsies of cutaneous tumors and normal skin were incubated with the lectins-AE, and chemiluminescence was quantified and expressed as Relative Light Units (RLU). Results. Actinic keratosis (AK), keratoacanthoma (KA), squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) showed lower expression of α -D-glucose/mannose and α -L-fucose residues compared to normal tissue. Cutaneous tumors displayed higher expression of Gal- β (1-3)-GalNAc residues than normal tissue. AK and SCC exhibited higher expression of Neu5Ac- α (2,3)Gal residues than normal epidermis. KA and BCC showed equivalent RLU values compared to normal tissue. Lectin histochemiluminescence allowed quantitative assessment of the carbohydrate expression in cutaneous tissues, contributing to eliminate the subjectivity of conventional techniques used in the histopathological diagnosis.

The anatomy and physiology of the suspensory apparatus of the distal phalanx.

PubMed

Pollitt, Christopher C

2010-04-01

The equine hoof capsule protects the softer, more sensitive, structures within. Failure of the connection between hoof and bone (suspensory apparatus of the distal phalanx or SADP) results in the crippling lameness of laminitis. Active basal cell proliferation occurs principally in tubular hoof and proximal and distal lamellae. The remaining lamellae are virtually non-proliferative and the hoof wall moves past the stationary distal phalanx, by controlled activation and inhibition of constituent proteases. The lamellar corium derives most of its blood supply from the branches of the terminal arch which perforate the distal phalanx. Valveless veins within the foot can be exploited clinically for retrograde venous therapy or contrast radiography (venography). The basement membrane (BM) forms the interface between the lamellar epidermis and the adjacent dermis and the plasma membrane of each lamellar basal cell is attached to the BM by numerous electron dense adhesion plaques or hemidesmosomes the ultimate attachment unit of the SADP. Laminitis destroys and dislocates the BM and its components and without an intact, functional BM, the structure and function of the lamellar epidermis is pathologically compromised. Transcription and activation of constituent proteases occurs in normal hoof lamellae but in increased amounts during laminitis. Copyright 2010 Elsevier Inc. All rights reserved.

The radial growth phase of malignant melanoma: multi-phase modelling, numerical simulations and linear stability analysis.

PubMed

Ciarletta, P; Foret, L; Ben Amar, M

2011-03-06

Cutaneous melanoma is disproportionately lethal despite its relatively low incidence and its potential for cure in the early stages. The aim of this study is to foster understanding of the role of microstructure on the occurrence of morphological changes in diseased skin during melanoma evolution. The authors propose a biomechanical analysis of its radial growth phase, investigating the role of intercellular/stromal connections on the initial stages of epidermis invasion. The radial growth phase of a primary melanoma is modelled within the multi-phase theory of mixtures, reproducing the mechanical behaviour of the skin layers and of the epidermal-dermal junction. The theoretical analysis takes into account those cellular processes that have been experimentally observed to disrupt homeostasis in normal epidermis. Numerical simulations demonstrate that the loss of adhesiveness of the melanoma cells both to the basal laminae, caused by deregulation mechanisms of adherent junctions, and to adjacent keratynocytes, consequent to a downregulation of E-cadherin, are the fundamental biomechanical features for promoting tumour initiation. Finally, the authors provide the mathematical proof of a long wavelength instability of the tumour front during the early stages of melanoma invasion. These results open the perspective to correlate the early morphology of a growing melanoma with the biomechanical characteristics of its micro-environment.

Remodelling of three-dimensional organization of the nucleus during terminal keratinocyte differentiation in the epidermis

PubMed Central

Gdula, Michal R.; Poterlowicz, Krzysztof; Mardaryev, Andrei N.; Sharov, Andrey A.; Peng, Y.; Fessing, Michael Y.; Botchkarev, Vladimir A.

2014-01-01

The nucleus of epidermal keratinocytes is a complex and highly compartmentalized organelle, whose structure is markedly changed during terminal differentiation and transition of the genome from a transcriptionally active state seen in the basal and spinous epidermal cells to a fully inactive state in the keratinized cells of the cornified layer. Here, using multi-color confocal microscopy, followed by computational image analysis and mathematical modelling, we demonstrate that in normal mouse foot-pad epidermis transition of keratinocytes from basal epidermal layer to the granular layer is accompanied by marked differences in nuclear architecture and micro-environment including: i) decrease of the nuclear volume, ii) decrease in expression of the markers of transcriptionally-active chromatin; iii) internalization and decrease in the number of nucleoli; iv) increase in the number of pericentromeric heterochromatic clusters; v) increase in the frequency of associations between pericentromeric clusters, chromosomal territory 3, and nucleoli. These data suggest a role for nucleoli and pericentromeric heterochromatin clusters as organizers of nuclear micro-environment required for proper execution of gene expression programs in differentiating keratinocytes and provide important background information for further analyses of alterations in the topological genome organization seen in pathological skin conditions including disorders of epidermal differentiation and epidermal tumors. PMID:23407401

Gene Targeting of Envoplakin, a Cytoskeletal Linker Protein and Precursor of the Epidermal Cornified Envelope

PubMed Central

Määttä, Arto; DiColandrea, Teresa; Groot, Karen; Watt, Fiona M.

2001-01-01

Envoplakin, a member of the plakin family of cytoskeletal linker proteins, is localized in desmosomes of stratified epithelial cells and is a component of the epidermal cornified envelope. Gene targeting in mouse embryonic stem cells was used to generate a null allele of envoplakin. No envoplakin transcripts from the targeted allele could be detected in the skin of newborn mice. Mice homozygous for the targeted allele were born in the normal Mendelian ratio and were fertile. They did not develop any discernible pathological phenotype up to the age of 1 year. The ultrastructural appearance of cornified envelopes from adult epidermis was indistinguishable between wild-type and knockout mice, and there was no evidence that the absence of envoplakin affected the subcellular distribution of periplakin or desmoplakin, two other plakins found in desmosomes. The proportion of immature cornified envelopes in the epidermis of newborn mice was greater in envoplakin-null animals than in heterozygous littermates or wild-type mice, and the envelopes had a larger surface area. This correlated with a slight delay in barrier acquisition during embryonic development. We conclude that although envoplakin is part of the scaffolding on which the cornified envelope is assembled, it is not essential for envelope formation or epidermal barrier function. PMID:11564887

Skin aging in patients with acquired immunodeficiency syndrome.

PubMed

de Aquino Favarato, Grace Kelly Naves; da Silva, Aline Cristina Souza; Oliveira, Lívia Ferreira; da Fonseca Ferraz, Mara Lúcia; de Paula Antunes Teixeira, Vicente; Cavellani, Camila Lourencini

2016-10-01

To evaluate the histomorphometric skin changes over aging patients with autopsied acquired immunodeficiency syndrome (AIDS). In 29 skin fragments of autopsied elderly (older than 50 years) and nonelderly patients with AIDS, epidermal thickness, the number of layers, the diameter of cells, the percentage of collagen and elastic fibers in the dermis, and the number and morphology of Langerhans cells were assessed. Statistical analysis was performed by SigmaStat 2.03 program. The thickness of the epidermis (92.55 × 158.94 μm), the number of layers (7 × 9 layers), and the diameter of the cells (13.27 × 17.6 μm) were statistically lower among the elderly. The quantity of collagen fibers (9.68 × 14.11%) and elastic fibers (11.89 × 15.31%) was also significantly lower in the elderly. There was a decrease in total (10.61 × 12.38 cel/mm(2)) and an increase in immature Langerhans cells (6.31 × 4.98 cel/mm(2)) in elderly patients with AIDS. The aging of the skin of patients with AIDS is amended in different histomorphometric aspects, the epidermis constituents suffer less pronounced changes in normal aging, and the dermis has more intense changes in elastic fibers and collagen. Copyright © 2016 Elsevier Inc. All rights reserved.

Skin welding using pulsed laser radiation and a dye

NASA Astrophysics Data System (ADS)

Fried, Nathaniel M.; Walsh, Joseph T., Jr.

1998-07-01

Previous skin welding studies have used continuous wave (CW) delivery of radiation. However, heat diffusion during irradiation prevents strong welds from being achieved without creating large zones of thermal damage to surrounding tissue. This damage may prevent normal wound healing. Strong welds and minimal thermal damage can be achieved by introducing a dye and delivering the radiation in a pulsed mode. Two-cm-long, full-thickness incisions were made in guinea pig skin. India ink was used as an absorber, and egg white albumin was used as an adhesive. A 5-mm-diameter spot of CW, 1.06-micrometer Nd:YAG laser radiation was scanned over the weld site, producing 100 millisecond pulses. The cooling time between scans and number of scans was varied. Thermal damage zones were measured using a transmission polarizing microscope to identify birefringence changes in tissue. Tensile strengths were measured using a tensiometer. For pulsed welding and long cooling times, weld strengths of 2.4 kg/cm2 were measured, and thermal damage to the epidermis was limited to approximately 500 micrometers. With CW welding, comparable weld strengths resulted in approximately 2700 micrometer of thermal damage. CW laser radiation weld strengths were only 0.6 kg/cm2 when thermal damage in the epidermis was limited to approximately 500 micrometers.

The radial growth phase of malignant melanoma: multi-phase modelling, numerical simulations and linear stability analysis

PubMed Central

Ciarletta, P.; Foret, L.; Ben Amar, M.

2011-01-01

Cutaneous melanoma is disproportionately lethal despite its relatively low incidence and its potential for cure in the early stages. The aim of this study is to foster understanding of the role of microstructure on the occurrence of morphological changes in diseased skin during melanoma evolution. The authors propose a biomechanical analysis of its radial growth phase, investigating the role of intercellular/stromal connections on the initial stages of epidermis invasion. The radial growth phase of a primary melanoma is modelled within the multi-phase theory of mixtures, reproducing the mechanical behaviour of the skin layers and of the epidermal–dermal junction. The theoretical analysis takes into account those cellular processes that have been experimentally observed to disrupt homeostasis in normal epidermis. Numerical simulations demonstrate that the loss of adhesiveness of the melanoma cells both to the basal laminae, caused by deregulation mechanisms of adherent junctions, and to adjacent keratynocytes, consequent to a downregulation of E-cadherin, are the fundamental biomechanical features for promoting tumour initiation. Finally, the authors provide the mathematical proof of a long wavelength instability of the tumour front during the early stages of melanoma invasion. These results open the perspective to correlate the early morphology of a growing melanoma with the biomechanical characteristics of its micro-environment. PMID:20656740

Immunohistochemical demonstration of keratins in the epidermal layers of the Malayan pangolin (Manis javanica), with remarks on the evolution of the integumental scale armour.

PubMed

Meyer, W; Liumsiricharoen, M; Suprasert, A; Fleischer, L G; Hewicker-Trautwein, M

2013-09-16

Using immunohistochemistry, the study demonstrates the distribution of keratins (pan-keratin with CK1-8, 10, 14-16, 19; keratins CK1, 5, 6, 9, 10; hair keratins AE13, AE14) in the epidermis of the Malayan pangolin (Manis javanica). A varying reaction spectrum was observed for pan-keratin, with body region-dependent negative to very strong reaction intensities. The dorsolateral epidermis exhibited positive reactions only in its vital layers, whereas the abdominal epidermis showed strong positive reactions in the soft two outer strata. The single acidic and basic-to-neutral (cyto)keratins produced clear variations compared to the pan-keratin tinging. E.g., CK1 appeared in all epidermal layers of both body regions, except for the ventral stratum corneum, whereas CK5, 6, 9, 10 were restricted to the soft ventral epidermis. Here, distinctly positive reactions were confined to the stratum granulosum, except for CK6 that appeared in the soft stratum corneum. A different staining pattern was obvious for the hair keratins, i.e., positive reactions of AE13 concentrated only in the granular layer of the dorsal epidermis. In the abdominal epidermis, remarkable tinging for AE14 was visible in the stratum basale, decreasing toward the corneal layer, but was also found in the outer root sheath cells of the hair follicles in the ventral body part. Our findings are discussed related to the evolution of the horny dorsal scales of the pangolin, which may have started from the tail root, projecting forward to the head.

Cutaneous larva migrans syndrome: a case report.

PubMed

Tekely, Emilia; Szostakiewicz, Beata; Wawrzycki, Bartłomiej; Kądziela-Wypyska, Grażyna; Juszkiewicz-Borowiec, Maria; Pietrzak, Aldona; Chodorowska, Grażyna

2013-04-01

Cutaneous larva migrans (CML) is a frequent parasitic infestation caused by migration of animal hookworm larvae into the human epidermis. This skin disease is common in warmer climates among people, who have contact with contaminated soil. Clinical manifestation of CML is an itchy, erythematous, linear tract, which appears days to even months after exposure to infested sand or soil. Diagnosis is established on the clinical presentation. We describe a case of CML acquired during a holiday in Brazil.

Cutaneous larva migrans syndrome: a case report

PubMed Central

Szostakiewicz, Beata; Wawrzycki, Bartłomiej; Kądziela-Wypyska, Grażyna; Juszkiewicz-Borowiec, Maria; Pietrzak, Aldona; Chodorowska, Grażyna

2013-01-01

Cutaneous larva migrans (CML) is a frequent parasitic infestation caused by migration of animal hookworm larvae into the human epidermis. This skin disease is common in warmer climates among people, who have contact with contaminated soil. Clinical manifestation of CML is an itchy, erythematous, linear tract, which appears days to even months after exposure to infested sand or soil. Diagnosis is established on the clinical presentation. We describe a case of CML acquired during a holiday in Brazil. PMID:24278060

Selective Ablation of Ctip2/Bcl11b in Epidermal Keratinocytes Triggers Atopic Dermatitis-Like Skin Inflammatory Responses in Adult Mice

PubMed Central

Guha, Gunjan; Li, Shan; Kyrylkova, Kateryna; Kioussi, Chrissa; Leid, Mark; Ganguli-Indra, Gitali; Indra, Arup K.

2012-01-01

Background Ctip2 is crucial for epidermal homeostasis and protective barrier formation in developing mouse embryos. Selective ablation of Ctip2 in epidermis leads to increased transepidermal water loss (TEWL), impaired epidermal proliferation, terminal differentiation, as well as altered lipid composition during development. However, little is known about the role of Ctip2 in skin homeostasis in adult mice. Methodology/Principal Findings To study the role of Ctip2 in adult skin homeostasis, we utilized Ctip2ep−/− mouse model in which Ctip2 is selectively deleted in epidermal keratinocytes. Measurement of TEWL, followed by histological, immunohistochemical, and RT-qPCR analyses revealed an important role of Ctip2 in barrier maintenance and in regulating adult skin homeostasis. We demonstrated that keratinocytic ablation of Ctip2 leads to atopic dermatitis (AD)-like skin inflammation, characterized by alopecia, pruritus and scaling, as well as extensive infiltration of immune cells including T lymphocytes, mast cells, and eosinophils. We observed increased expression of T-helper 2 (Th2)-type cytokines and chemokines in the mutant skin, as well as systemic immune responses that share similarity with human AD patients. Furthermore, we discovered that thymic stromal lymphopoietin (TSLP) expression was significantly upregulated in the mutant epidermis as early as postnatal day 1 and ChIP assay revealed that TSLP is likely a direct transcriptional target of Ctip2 in epidermal keratinocytes. Conclusions/Significance Our data demonstrated a cell-autonomous role of Ctip2 in barrier maintenance and epidermal homeostasis in adult mice skin. We discovered a crucial non-cell autonomous role of keratinocytic Ctip2 in suppressing skin inflammatory responses by regulating the expression of Th2-type cytokines. It is likely that the epidermal hyperproliferation in the Ctip2-lacking epidermis may be secondary to the compensatory response of the adult epidermis that is defective in barrier functions. Our results establish an initiating role of epidermal TSLP in AD pathogenesis via a novel repressive regulatory mechanism enforced by Ctip2. PMID:23284675

Dermal absorption of benzo[a]pyrene into human skin from soil: Effect of artificial weathering, concentration, and exposure duration.

PubMed

Peckham, Trevor K; Shirai, Jeffry H; Bunge, Annette L; Lowney, Yvette W; Ruby, Michael V; Kissel, John C

2017-11-01

In vitro assessments of 14 C-benzo[a]pyrene (BaP) absorption through human epidermis were conducted with the sub-63-μm fraction of four test soils containing different amounts of organic and black carbon. Soils were artificially weathered for eight weeks and applied to epidermis at nominal BaP concentrations of 3 and 10 mg/kg for 8 or 24 h. Experiments were also conducted at 24 h with unweathered soils and with BaP deposited onto skin from acetone at a comparable chemical load. For the weathered soils, absorption was independent of the amount of organic or black carbon, the mass in the receptor fluid was proportional to exposure duration but independent of concentration, and the mass recovered in the skin after washing was proportional to concentration and independent of exposure time. Results from the weathered and unweathered soils were similar except for the mass recovered in the washed skin, which was lower for the weathered soil only at the higher concentration. We hypothesize that chemical concentrations exceeded the BaP sorption capacity accessible within the artificial weathering timeframe for all soils tested, and that BaP mass in the washed skin was dominated by particles that were not removed by washing. Fluxes into and through skin from soils were lower by an order of magnitude than from acetone-deposited BaP.

Deletion of epidermal Rac1 inhibits HPV-8 induced skin papilloma formation and facilitates HPV-8- and UV-light induced skin carcinogenesis

PubMed Central

Deshmukh, Jayesh; Pofahl, Ruth; Pfister, Herbert; Haase, Ingo

2016-01-01

Overexpression and increased activity of the small Rho GTPase Rac1 has been linked to squamous cell carcinoma of the epidermis and mucosa in humans. Targeted deletion of Rac1 or inhibition of Rac1 activity in epidermal keratinocytes reduced papilloma formation in a chemical skin carcinogenesis mouse model. However, a potential role of Rac1 in HPV- and UV-light induced skin carcinogenesis has not been investigated so far, solar UV radiation being an important carcinogen to the skin. To investigate this, we deleted Rac1 or modulated its activity in mice with transgenic expression of Human papilloma virus type-8 (HPV-8) in epidermal keratinocytes. Our data show that inhibition or deletion of Rac1 results in reduced papilloma formation upon UV-irradiation with a single dose, whereas constitutive activation of Rac1 strongly increases papilloma frequency in these mice. Surprisingly, we observed that, upon chronic UV-irradiation, the majority of mice with transgenic expression of HPV-8 and epidermis specific Rac1 deletion developed squamous cell carcinomas. Taken together, our data show that Rac1 exerts a dual role in skin carcinogenesis: its activation is, on one hand, required for HPV-8- and UV-light induced papilloma formation but, on the other, suppresses the development of squamous cell carcinomas. PMID:27506937

Deletion of epidermal Rac1 inhibits HPV-8 induced skin papilloma formation and facilitates HPV-8- and UV-light induced skin carcinogenesis.

PubMed

Deshmukh, Jayesh; Pofahl, Ruth; Pfister, Herbert; Haase, Ingo

2016-09-06

Overexpression and increased activity of the small Rho GTPase Rac1 has been linked to squamous cell carcinoma of the epidermis and mucosa in humans. Targeted deletion of Rac1 or inhibition of Rac1 activity in epidermal keratinocytes reduced papilloma formation in a chemical skin carcinogenesis mouse model. However, a potential role of Rac1 in HPV- and UV-light induced skin carcinogenesis has not been investigated so far, solar UV radiation being an important carcinogen to the skin.To investigate this, we deleted Rac1 or modulated its activity in mice with transgenic expression of Human papilloma virus type-8 (HPV-8) in epidermal keratinocytes. Our data show that inhibition or deletion of Rac1 results in reduced papilloma formation upon UV-irradiation with a single dose, whereas constitutive activation of Rac1 strongly increases papilloma frequency in these mice. Surprisingly, we observed that, upon chronic UV-irradiation, the majority of mice with transgenic expression of HPV-8 and epidermis specific Rac1 deletion developed squamous cell carcinomas. Taken together, our data show that Rac1 exerts a dual role in skin carcinogenesis: its activation is, on one hand, required for HPV-8- and UV-light induced papilloma formation but, on the other, suppresses the development of squamous cell carcinomas.

Plant stem cells as innovation in cosmetics.

PubMed

Moruś, Martyna; Baran, Monika; Rost-Roszkowska, Magdalena; Skotnicka-Graca, Urszula

2014-01-01

The stem cells thanks to their ability of unlimited division number or transformation into different cell types creating organs, are responsible for regeneration processes. Depending on the organism in which the stem cells exists, they divide to the plant or animal ones. The later group includes the stem cells existing in both embryo's and adult human's organs. It includes, among others, epidermal stem cells, located in the hair follicle relieves and also in its basal layers, and responsible for permanent regeneration of the epidermis. Temporary science looks for method suitable for stimulation of the epidermis stem cells, amongst the other by delivery of e.g., growth factors for proliferation that decrease with the age. One of the methods is the use of the plant cell culture technology, including a number of methods that should ensure growth of plant cells, issues or organs in the environment with the microorganism-free medium. It uses abilities of the different plant cells to dedifferentiation into stem cells and coming back to the pluripotent status. The extracts obtained this way from the plant stem cells are currently used for production of both common or professional care cosmetics. This work describes exactly impact of the plant stem cell extract, coming from one type of the common apple tree (Uttwiler Spätlauber) to human skin as one of the first plant sorts, which are used in cosmetology and esthetic dermatology.

Cytokine-induced CEACAM1 expression on keratinocytes is characteristic for psoriatic skin and contributes to a prolonged lifespan of neutrophils.

PubMed

Rahmoun, Massilva; Molès, Jean-Pierre; Pedretti, Nathalie; Mathieu, Marc; Fremaux, Isabelle; Raison-Peyron, Nadia; Lecron, Jean-Claude; Yssel, Hans; Pène, Jérôme

2009-03-01

Carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1) is a cell-surface glycoprotein, belonging to the carcinoembryonic antigen family, expressed by human neutrophils, epithelial cells, activated T and NK cells. CEACAM1 is expressed as a cell-surface molecule with different isoforms or can be secreted as a soluble protein. Here, we show that keratinocytes in the outer epidermal layer of psoriatic skin express CEACAM1, unlike those in healthy skin or in cutaneous lesions of patients with atopic or nummular dermatitis. Stimulation of primary human keratinocytes or in vitro reconstituted epidermis with culture supernatants of activated psoriatic lesion-infiltrating T cells, IFN-gamma or oncostatin M, but not IL-17, induced the expression of transcripts for the CEACAM1-long and -short isoforms and cell-surface CEACAM1, whereas soluble CEACAM1 was not produced. The uppermost layers of the epidermis in psoriatic lesions also contain neutrophils, a cell type with inflammatory and antimicrobial properties. Coculture of CEACAM1-expressing keratinocytes or CHO transfectants with neutrophils delayed spontaneous apoptosis of the latter cells. These results show that cytokine-induced cell-surface expression of CEACAM1 by keratinocytes in the context of a psoriatic environment might contribute to the persistence of neutrophils and thus to ongoing inflammation and the decreased propensity for skin infection, typical for patients with psoriasis.

Morphological study on the pressure ulcer-like dermal lesions formed in the rat heel skin after transection of the sciatic nerves.

PubMed

Haba, Daijiro; Minami, Chie; Miyagawa, Miki; Arakawa, Takamitsu; Miki, Akinori

2017-01-01

Due to transection of bilateral sciatic nerves, pressure ulcer-like dermal lesion occurred in the hairy skin covering of the heel skin in almost all rats. In the present study, chronological changes of the rat heel skin after the transection were morphologically and immunohistochemically examined. In the heel skin, redness and swelling began by 3days after the operation, and open wound formed by 17days. At the redness and swelling stage, edema extensively occurred in the dermis. At the thickening stage, the epidermis at the pressed site became transiently thicker, and at the whitening stage, rapidly thinner. At these stages, the epidermis in the skin surrounding the pressed site became gradually thicker. At the yellow scar stage, the skin was covered only by necrotic tissues and horny layer. These layers were scratched during walking and turning, and the yellow scar stage became the open wound stage. Inflammatory reaction began at the thickening stage, and at the yellow scar and open wound stages, necrosis, infiltration of inflammatory cells and dilation of small blood vessels were observed. These morphological features are quite similar to those in the human pressure ulcer. These findings suggest that these dermal injuries could compare the human pressure ulcer for medical treatment and depressurization in future study. Copyright © 2016 Elsevier GmbH. All rights reserved.

Human papillomavirus E6/E7 oncogenes promote mouse ear regeneration by increasing the rate of wound re-epithelization and epidermal growth.

PubMed

Valencia, Concepción; Bonilla-Delgado, José; Oktaba, Katarzyna; Ocádiz-Delgado, Rodolfo; Gariglio, Patricio; Covarrubias, Luis

2008-12-01

Mammals have limited regeneration capacity. We report here that, in transgenic mice (Tg(bK6-E6/E7)), the expression of the E6/E7 oncogenes of human papilloma virus type 16 (HPV16) under the control of the bovine keratin 6 promoter markedly improves the mouse's capacity to repair portions of the ear after being wounded. Increased repair capacity correlates with an increased number of epidermal proliferating cells. In concordance with the expected effects of the E6 and E7 oncogenes, levels of p53 decreased and those of p16 in epidermal cells increased. In addition, we observed that wound re-epithelization proceeded faster in transgenic than in wild-type animals. After the initial re-epithelization, epidermal cell migration from the intact surrounding tissue appears to be a major contributor to the growing epidermis, especially in the repairing tissue of transgenic mice. We also found that there is a significantly higher number of putative epidermal stem cells in Tg(bK6-E6/E7) than in wild-type mice. Remarkably, hair follicles and cartilage regenerated within the repaired ear tissue, without evidence of tumor formation. We propose that the ability to regenerate ear portions is limited by the capacity of the epidermis to repair itself and grow.

In vitro percutaneous absorption studies and in vivo evaluation of anti-inflammatory activity of essential fatty acids (EFA) from fish oil extracts.

PubMed

Puglia, Carmelo; Tropea, Salvatore; Rizza, Luisa; Santagati, Natale Alfredo; Bonina, Francesco

2005-08-11

The aim of the present study was to evaluate the in vitro percutaneous absorption and the in vivo anti-inflammatory activity of EPA and DHA fatty acids from three oily extracts, obtained by acetonic extractions from the entrails of different varieties of Mediterranean fishes such as mackerel (Scomber scombrus), sardine (Sardina pilchardus) and horse mackerel (Trachurus mediterraneus). In the first part of our research, we focused our attention on the characterization of the oily extracts to determine their omega-3 polyunsaturated fatty acid content, then, we evaluated the in vitro percutaneous absorption through excised human skin (stratum corneum/epidermis membranes; SCE) of EPA and DHA contained in the extracts. In the second part, the fish oil which guaranteed the best in vitro permeation profile of these omega-3 fatty acids was studied in order to evaluate its inhibiting ability towards the in vivo UVB-induced skin erythema. From the results obtained, all the fish oils tested in this study presented significant amounts of omega-3 fatty acids EPA and DHA, and particularly sardine oil extract showed higher concentrations of these substances compared to the other two fish oils. The in vitro experiments revealed interesting fluxes of these compounds from sardine extract through the stratum corneum/epidermis membranes and an appreciable anti-inflammatory activity against UVB-induced erythema in human volunteers was also observed.

Concentration dependency in nicotine skin penetration flux from aqueous solutions reflects vehicle induced changes in nicotine stratum corneum retention.

PubMed

Kuswahyuning, Rina; Roberts, Michael S

2014-06-01

This study sought to understand the mechanism by which the steady state flux of nicotine across the human skin from aqueous solutions is markedly decreased at higher nicotine concentrations. Nicotine's steady state flux through human epidermis and its amount in the stratum corneum for a range of aqueous nicotine solutions was determined using Franz diffusion cells, with the nicotine analysed by high performance liquid chromatography (HPLC). Nicotine's thermodynamic activity in the various solutions was estimated from its partial vapour pressure and stratum corneum hydration was determined using a corneometer. The amount of nicotine retained in the stratum corneum was estimated from the nicotine amount found in individual stratum corneum tape strips and a D-Squame determined weight for each strip. The observed steady state flux of nicotine across human epidermis was found to show a parabolic dependence on nicotine concentration, with the flux proportional to its thermodynamic activity up to a concentration of 48% w/w. The nicotine retention in the stratum corneum showed a similar dependency on concentration whereas the diffusivity of nicotine in the stratum corneum appeared to be concentration independent. This retention, in turn, could be estimated from the extent of stratum corneum hydration and the nicotine concentration in the applied solution and volume of water in the skin. Nonlinear dependency of nicotine skin flux on its concentration results from a dehydration induced decrease in its stratum corneum retention at higher concentration and not dehydration induced changes nicotine diffusivity in the stratum corneum.

Cutaneous estradiol permeation, penetration and metabolism in pig and man.

PubMed

Mahmoud, A; Haberland, A; Dürrfeld, M; Heydeck, D; Wagner, S; Schafer-Korting, M

2005-01-01

Drug development in dermatotherapy and also development of transdermal therapeutic systems (TTS) demand high-predictive in vitro models to estimate drug levels in skin and systemic uptake. Here we compare three ready-to-use models, reconstructed human epidermis, split porcine skin and the perfused porcine forelimb. 17beta-Estradiol (E(2)), which is highly metabolized by skin cells, serves as model drug since E(2) application is of high relevance in hormone replacement therapy while topical E(2) may promote wound healing. E(2) TTS, gel and an ethanolic solution were investigated for cutaneous penetration, permeation and metabolism. E(2) TTS enabled an E(2) uptake of 42.9% of the applied dose accompanied by a high percentage of E(2) metabolism (30% of the penetrated dose) in the perfused porcine forelimb. In Franz cell experiments with reconstructed human epidermis and split porcine skin, the gel allowed an E(2) uptake of 41.7 and 22.9% of the applied dose accompanied by a high E(2) metabolism (42.6 and 28.6% of the penetrated dose). Due to toxic effects of the vehicle, this was not true with an ethanolic solution, then E(2) permeation and metabolism were clearly diminished. Most importantly, the in vitro models proved to be predictive with respect to the E(2)/estrone ratio in female plasma under transdermal hormone replacement therapy. In vitro tests should reduce the need for both animal and human studies for cutaneous uptake and metabolism in the future. Copyright 2005 S. Karger AG, Basel.

Mechanistic Analysis of Human Skin Distribution and Follicular Targeting of Adapalene-Loaded Biodegradable Nanospheres With an Insight Into Hydrogel Matrix Influence, In Vitro Skin Irritation, and In Vivo Tolerability.

PubMed

Sallam, Marwa Ahmed; Marín Boscá, María Teresa

2017-10-01

This work aimed at the development of a biocompatible, non-oily nanomedicine for follicular delivery of adapalene (AD) ameliorating its irritation potential for convenient localized topical treatment of acne vulgaris. AD was efficiently incorporated into poly-ε-caprolactone nanospheres (NS) with an encapsulation efficiency of 84.73% ± 1.52%, a particle size of 107.5 ± 8.19 nm, and zeta potential of -13.1 mV demonstrating a sustained-release behavior. The AD-NS were embedded in either hydroxypropyl methylcellulose (HPMC) or hyaluronate (HA) gel. The ex vivo human skin dermatokinetics of AD from each system was studied. The nanoparticles dispersion showed significantly higher AD retention in the epidermis and dermis than AD suspension. NS-HPMC decreased whereas NS-HA increased AD retained in all the skin layers. The fate of the NS and the role of the hydrogel in modulating skin distribution was evaluated by confocal laser scanning microscopy (CLSM) imaging of fluorescently labeled NS. CLSM illustrated follicular localization of the florescent NS. HPMC gel restricted the presence of NS to the stratum corneum and epidermis. HA gel enhanced the penetration of NS to all the skin layers. In vitro skin irritation using human dermal fibroblasts and in vivo animal tolerability studies were performed. Accordingly, HA gel-dispersed AD-NS presented a nonirritant compromised cosmeceutical formulation suitable for oily acneic skin. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Multiple-reflection model of human skin and estimation of pigment concentrations

NASA Astrophysics Data System (ADS)

Ohtsuki, Rie; Tominaga, Shoji; Tanno, Osamu

2012-07-01

We describe a new method for estimating the concentrations of pigments in the human skin using surface spectral reflectance. We derive an equation that expresses the surface spectral reflectance of the human skin. First, we propose an optical model of the human skin that accounts for the stratum corneum. We also consider the difference between the scattering coefficient of the epidermis and that of the dermis. We then derive an equation by applying the Kubelka-Munk theory to an optical model of the human skin. Unlike a model developed in a recent study, the present equation considers pigments as well as multiple reflections and the thicknesses of the skin layers as factors that affect the color of the human skin. In two experiments, we estimate the pigment concentrations using the measured surface spectral reflectances. Finally, we confirm the feasibility of the concentrations estimated by the proposed method by evaluating the estimated pigment concentrations in the skin.

Black Molds and Melanized Yeasts Pathogenic to Humans

PubMed Central

Chowdhary, Anuradha; Perfect, John; de Hoog, G. Sybren

2015-01-01

A review is given of melanized fungi involved in human infection, including species forming budding cells and strictly filamentous representatives. Classically, they are known as “phaeoid” or “dematiaceous” fungi, and, today, agents are recognized to belong to seven orders of fungi, of which the Chaetothyriales and Pleosporales are the most important. Infections range from cutaneous or pulmonary colonization to systemic or disseminated invasion. Subcutaneous involvement, either primary or after dissemination, may lead to host tissue proliferation of dermis or epidermis. Particularly in the Chaetothyriales, subcutaneous and systemic infections may occur in otherwise apparently healthy individuals. Infections are mostly chronic and require extended antifungal therapy and/or surgery. PMID:25384772

Self-Powered Real-Time Arterial Pulse Monitoring Using Ultrathin Epidermal Piezoelectric Sensors.

PubMed

Park, Dae Yong; Joe, Daniel J; Kim, Dong Hyun; Park, Hyewon; Han, Jae Hyun; Jeong, Chang Kyu; Park, Hyelim; Park, Jung Gyu; Joung, Boyoung; Lee, Keon Jae

2017-10-01

Continuous monitoring of an arterial pulse using a pressure sensor attached on the epidermis is an important technology for detecting the early onset of cardiovascular disease and assessing personal health status. Conventional pulse sensors have the capability of detecting human biosignals, but have significant drawbacks of power consumption issues that limit sustainable operation of wearable medical devices. Here, a self-powered piezoelectric pulse sensor is demonstrated to enable in vivo measurement of radial/carotid pulse signals in near-surface arteries. The inorganic piezoelectric sensor on an ultrathin plastic achieves conformal contact with the complex texture of the rugged skin, which allows to respond to the tiny pulse changes arising on the surface of epidermis. Experimental studies provide characteristics of the sensor with a sensitivity (≈0.018 kPa -1 ), response time (≈60 ms), and good mechanical stability. Wireless transmission of detected arterial pressure signals to a smart phone demonstrates the possibility of self-powered and real-time pulse monitoring system. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Epidermal growth in the bottlenose dolphin, Tursiops truncatus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hicks, B.D.; St. Aubin, D.J.; Geraci, J.R.

1985-07-01

Epidermal growth in two mature female bottlenose dolphins, Tursiops truncatus, was investigated by following the movement of a cohort of tritiated thymidine-labeled epidermal cells for 59 days. The majority of the cells migrated in a cluster which was estimated to reach the skin surface in 73 days. The authors calculate that the outermost cell layer is sloughed 12 times per day. Turnover time and sloughing rate are estimated to be 1.7 times longer and 8.5 times faster than the respective values for epidermal cell kinetics in humans. This apparent inconsistency of slow transit time and rapid sloughing rate is reconciledmore » by the convoluted structure of the stratum germinativum in the dolphin which results in a ratio of germinatival to superficial cells of 876:1. The stratum germinativum of dolphin epidermis appears to lack morphologically distinct, spatially segregated subpopulations of anchoring and stem cells. Dolphin epidermis has a large capacity for cell population, relatively long turnover time, and rapid sloughing rate. The adaptive advantages of these characteristics are discussed.« less

Cytologic features of hyperplastic epidermis.

PubMed

Eng, A M; Worobec, S

1977-10-01

The cytologic features of hyperplastic epidermis in common lesions such as verruca, seborrheic keratosis, condyloma accuminatum, fibroepithelial polyp, corn, radiodermatitis, prurigo nodularis, epidermal nevus, dermatofibroma, tricholemmona, inverted follicular keratosis and pseudoepitheliomatous hyperplasia were studied. Common, as well as distinguishing cytologic points are recognized.

A Rapid, Highly Efficient and Economical Method of Agrobacterium-Mediated In planta Transient Transformation in Living Onion Epidermis

PubMed Central

Xu, Kedong; Huang, Xiaohui; Wu, Manman; Wang, Yan; Chang, Yunxia; Liu, Kun; Zhang, Ju; Zhang, Yi; Zhang, Fuli; Yi, Liming; Li, Tingting; Wang, Ruiyue; Tan, Guangxuan; Li, Chengwei

2014-01-01

Transient transformation is simpler, more efficient and economical in analyzing protein subcellular localization than stable transformation. Fluorescent fusion proteins were often used in transient transformation to follow the in vivo behavior of proteins. Onion epidermis, which has large, living and transparent cells in a monolayer, is suitable to visualize fluorescent fusion proteins. The often used transient transformation methods included particle bombardment, protoplast transfection and Agrobacterium-mediated transformation. Particle bombardment in onion epidermis was successfully established, however, it was expensive, biolistic equipment dependent and with low transformation efficiency. We developed a highly efficient in planta transient transformation method in onion epidermis by using a special agroinfiltration method, which could be fulfilled within 5 days from the pretreatment of onion bulb to the best time-point for analyzing gene expression. The transformation conditions were optimized to achieve 43.87% transformation efficiency in living onion epidermis. The developed method has advantages in cost, time-consuming, equipment dependency and transformation efficiency in contrast with those methods of particle bombardment in onion epidermal cells, protoplast transfection and Agrobacterium-mediated transient transformation in leaf epidermal cells of other plants. It will facilitate the analysis of protein subcellular localization on a large scale. PMID:24416168

Epidermis architecture and material properties of the skin of four snake species

PubMed Central

Klein, Marie-Christin G.; Gorb, Stanislav N.

2012-01-01

On the basis of structural and experimental data, it was previously demonstrated that the snake integument consists of a hard, robust, inflexible outer surface (Oberhäutchen and β-layer) and softer, flexible inner layers (α-layers). It is not clear whether this phenomenon is a general adaptation of snakes to limbless locomotion or only to specific conditions, such as habitat and locomotion. The aim of the present study was to compare the structure and material properties of the outer scale layers (OSLs) and inner scale layers (ISLs) of the exuvium epidermis in four snake species specialized to live in different habitats: Lampropeltis getula californiae (terrestrial), Epicrates cenchria cenchria (generalist), Morelia viridis (arboreal) and Gongylophis colubrinus (sand-burrowing). Scanning electron microscopy (SEM) of skin cross sections revealed a strong variation in the epidermis structure between species. The nanoindentation experiments clearly demonstrated a gradient of material properties along the epidermis in the integument of all the species studied. The presence of such a gradient is a possible adaptation to locomotion and wear minimization on natural substrates. In general, the difference in both the effective elastic modulus and hardness of the OSL and ISL between species was not large compared with the difference in epidermis thickness and architecture. PMID:22896567

Role of Ca++ Influx via Epidermal TRP Ion Channels

DTIC Science & Technology

2014-10-01

determine the epidermis’ response to activation of TRP channels. 2 Keywords Amputation stump, irritant dermatitis , epidermis, skin barrier function, TRP...the personnel who is in contact with subjects. All these requirements were addressed satisfactorily. Impact We view the pilot finding that

Molecular basis of retinol anti-ageing properties in naturally aged human skin in vivo.

PubMed

Shao, Y; He, T; Fisher, G J; Voorhees, J J; Quan, T

2017-02-01

Retinoic acid has been shown to improve the aged-appearing skin. However, less is known about the anti-ageing effects of retinol (ROL, vitamin A), a precursor of retinoic acid, in aged human skin in vivo. This study aimed to investigate the molecular basis of ROL anti-ageing properties in naturally aged human skin in vivo. Sun-protected buttock skin (76 ± 6 years old, n = 12) was topically treated with 0.4% ROL and its vehicle for 7 days. The effects of topical ROL on skin epidermis and dermis were evaluated by immunohistochemistry, in situ hybridization, Northern analysis, real-time RT-PCR and Western analysis. Collagen fibrils nanoscale structure and surface topology were analysed by atomic force microscopy. Topical ROL shows remarkable anti-ageing effects through three major types of skin cells: epidermal keratinocytes, dermal endothelial cells and fibroblasts. Topical ROL significantly increased epidermal thickness by stimulating keratinocytes proliferation and upregulation of c-Jun transcription factor. In addition to epidermal changes, topical ROL significantly improved dermal extracellular matrix (ECM) microenvironment; increasing dermal vascularity by stimulating endothelial cells proliferation and ECM production (type I collagen, fibronectin and elastin) by activating dermal fibroblasts. Topical ROL also stimulates TGF-β/CTGF pathway, the major regulator of ECM homeostasis, and thus enriched the deposition of ECM in aged human skin in vivo. 0.4% topical ROL achieved similar results as seen with topical retinoic acid, the biologically active form of ROL, without causing noticeable signs of retinoid side effects. 0.4% topical ROL shows remarkable anti-ageing effects through improvement of the homeostasis of epidermis and dermis by stimulating the proliferation of keratinocytes and endothelial cells, and activating dermal fibroblasts. These data provide evidence that 0.4% topical ROL is a promising and safe treatment to improve the naturally aged human skin. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

In vitro analysis of the effect of alkyl-chain length of anionic surfactants on the skin by using a reconstructed human epidermal model.

PubMed

Yamaguchi, Fumiko; Watanabe, Shin-Ichi; Harada, Fusae; Miyake, Miyuki; Yoshida, Masaki; Okano, Tomomichi

2014-01-01

We investigated the effect of the alkyl-chain length of anionic surfactants on the skin using an in vitro model. The evaluated anionic surfactants were sodium alkyl sulfate (AS) and sodium fatty acid methyl ester sulfonate (MES), which had different alkyl-chain lengths (C8-C14). Skin tissue damage and permeability were examined using a reconstructed human epidermal model, LabCyte EPI-MODEL24. Skin tissue damage was examined by measuring cytotoxicity with an MTT assay. Liquid chromatography/tandem mass spectrometry (LC/MS-MS) and liquid chromatography/mass spectrometry (LC/MS) were used to detect surfactants that permeated into the assay medium through an epidermal model. To assess the permeation mechanism and cell damage caused by the surfactants through the epidermis, we evaluated the structural changes of Bovine Serum Albumin (BSA), used as a simple model protein, and the fluidity of 1,2-dipalmitoyl-sn-glycero-3-phosphpcholine (DPPC) liposome, which serves as one of the most abundant phospholipid models of living cell membranes in the epidermis. The effects of the surfactants on the proteins were measured using Circular Dichroism (CD) spectroscopy, while the effects on membrane fluidity were investigated by electron spin resonance (ESR) spectroscopy. ET50 (the 50% median effective time) increased as follows: C10 < C12 < C8 < C14 in AS and C8, C10 < C12 < C14 in MES. The order of permeation through the LabCyte EPI-MODEL24 was C10 > C12 > C14, for both AS and MES. For both AS and MES, the order parameter, which is the criteria for the microscopic viscosity of lipid bilayers, increased as follows: C10 < C12 < C14, which means the membrane fluidity is C10 > C12 > C14. It was determined that the difference in skin tissue damage in the LabCyte EPI-MODEL24 with C10 to C14 AS and MES was caused by the difference in permeation and cell membrane fluidity through the lipid bilayer path in the epidermis.

Nuclear localization of activated STAT6 and STAT3 in epidermis of prurigo nodularis.

PubMed

Fukushi, S; Yamasaki, K; Aiba, S

2011-11-01

Prurigo nodularis (PN) is a chronic dermatitis characterized by discrete, raised, and firm papulonodules with intense pruritus. The pathogenesis still remains to be elucidated. To clarify the role of Th1 and Th2 cytokines in the pathogenesis of PN. We examined the cytokine signatures, such as phosphorylation of STAT1, STAT3 and STAT6, HLA-DR and hyaluronan accumulation, to reveal the Th1 and Th2 cytokine influence on the lesional epidermis of PN. We first optimized antigen retrieval methods to detect these signatures with antibodies for phospho-STAT1 (pSTAT1), phospho-STAT3 (pSTAT3), phospho-STAT6 (pSTAT6), HLA-DR and hyaluronic acid binding protein (HABP) on the formalin-fixed paraffin-embedded sections of psoriasis, lichen planus and atopic dermatitis biopsy samples. Activation of STAT1 and STAT6 in epidermis by Th1 and Th2 cytokines was further confirmed in a cultured skin equivalent model treated with interferon-γ or interleukin (IL)-4/IL-13. With the relevant immunostaining methods, we examined the cytokine signatures in 22 cases of PN. The results revealed that (i) the entire epidermis of 19 cases was stained with anti-pSTAT6 antibody, (ii) 21 cases demonstrated nuclear staining with anti-pSTAT3 antibody, (iii) the entire epidermis of 21 cases was stained with HABP, (iv) the epidermis of eight cases showed scattered staining with anti-pSTAT1 antibody, and (v) six cases were positive for HLA-DR membrane expression. These data indicated that Th2 cytokines related to STAT6 activation together with some unknown stimuli that activate STAT3 play a principal role in the pathogenesis of PN. © 2011 The Authors. BJD © 2011 British Association of Dermatologists.

VASCULARIZED COMPOSITE ALLOGRAFT TRANSPLANT SURVIVAL IN MINIATURE SWINE: IS MHC TOLERANCE SUFFICIENT FOR ACCEPTANCE OF EPIDERMIS?

PubMed Central

Cetrulo, Curtis L.; Torabi, Radbeh; Scalea, Joseph R.; Shimizu, Akira; Leto Barone, Angelo A.; Gillon, Brad C.; Tasaki, Masayuki; Leonard, David A.; Cormack, Taylor A.; Villani, Vincenzo; Randolph, Mark A.; Sachs, David H.; Yamada, Kazuhiko

2014-01-01

Background We have previously reported that MGH miniature swine which had accepted class-I mismatched kidneys long-term (LT) following 12 days of high dose Cyclosporine (CyA), uniformly accepted donor-MHC matched kidneys without immunosuppression but rejected donor-MHC matched split-thickness skin grafts (STSG) by day 25, without changes in renal graft function or anti-donor in vitro responses. We have now tested whether this “split tolerance” would also be observed for the primarily-vascularized skin of vascularized composite allografts (VCAs). Methods Group 1 animals (n=3) received donor-MHC matched VCAs <70 days following primary kidney transplant (KTx). Group 2 animals (n=3) received a second donor-matched t KTx followed by a donor-matched VCA >200 days after primary KTx. Results Animals in Group 1 lost the epidermis on days 28, 30, and 40, with all other components of the VCAs remaining viable. Histology showed cellular infiltration localized to dermal-epidermal junction. One of 3 recipients of VCAs including epidermis in Group 2 accepted all components of the VCAs (>200 days). The other two recipients lost only the epidermis at day 45 and 85, with survival of the remainder of the VCA long-term. Conclusions All tissues of a VCA are accepted long-term on animals tolerant of class-I mismatched kidneys, with the exception of epidermis, the survival of which is markedly prolonged compared to STSG, but not indefinite. Exposure of tolerant animals to second donor-matched kidneys prior to VCA increases the longevity of the VCA epidermis, suggesting an increase in the immunomodulatory mechanisms associated with tolerance of the kidney. PMID:24056624

Tissue-engineered skin preserving the potential of epithelial cells to differentiate into hair after grafting.

PubMed

Larouche, Danielle; Cuffley, Kristine; Paquet, Claudie; Germain, Lucie

2011-03-01

The aim of this study was to evaluate whether tissue-engineered skin produced in vitro was able to sustain growth of hair follicles in vitro and after grafting. Different tissues were designed. Dissociated newborn mouse keratinocytes or newborn mouse hair buds (HBs) were added onto dermal constructs consisting of a tissue-engineered cell-derived matrix elaborated from either newborn mouse or adult human fibroblasts cultured with ascorbic acid. After 7-21 days of maturation at the air-liquid interface, no hair was noticed in vitro. Epidermal differentiation was observed in all tissue-engineered skin. However, human fibroblast-derived tissue-engineered dermis (hD) promoted a thicker epidermis than mouse fibroblast-derived tissue-engineered dermis (mD). In association with mD, HBs developed epithelial cyst-like inclusions presenting outer root sheath-like attributes. In contrast, epidermoid cyst-like inclusions lined by a stratified squamous epithelium were present in tissues composed of HBs and hD. After grafting, pilo-sebaceous units formed and hair grew in skin elaborated from HBs cultured 10-26 days submerged in culture medium in association with mD. However, the number of normal hair follicles decreased with longer culture time. This hair-forming capacity after grafting was not observed in tissues composed of hD overlaid with HBs. These results demonstrate that epithelial stem cells can be kept in vitro in a permissive tissue-engineered dermal environment without losing their potential to induce hair growth after grafting.

The unexplored avenues of human skin: electromagnetic properties in the sub-THz band

NASA Astrophysics Data System (ADS)

Feldman, Y.; Safrai, E.; Ben Ishai, P.; Puzenko, A.; Agranat, A. J.; Caduff, A.

2012-03-01

Recent studies of the minute morphology of the skin by optical coherence tomography showed that the sweat ducts in human skin become helically shaped tubes in the Epidermis and are filled with an aqueous solution. When considered as entities embedded in a dielectric media, they resemble helical antennas. The spectral response obtained by our computer simulations coincides with the analytical prediction of antenna theory and support this hypothesis, if a fast enough current mechanism exists in the duct. In particular the strongest spectral response of the simulation was noted around the predicted frequencies (240 GHz and 380 GHz) for the respective normal and axial modes of the helical structure. Furthermore, circular dichroism of the reflected electromagnetic field is a characteristic property of such helical antennas and it was shown that it is indeed a characteristic of the simulation model. Fast proton hopping is posited as the current mechanism. Consequently experimental evidence is presented that the spectral response of the skin in the sub-Terahertz region is governed by the level of activity of the perspiration system. This in turn is moderated by the Sympathetic Nerve Response and is demonstrated by the correlation to physiological stress as manifested by the pulse rate and the systolic blood pressure. These physical relaxations are tonic in nature (lasting more than a minute). Could the phasic characteristic of emotional excitation also be evident in the reflection coefficient? By applying techniques borrowed from psychiatric science we hope to answer this point in our paper.

Parameterization using Fourier series expansion of the diffuse reflectance of human skin to vary the concentration of the melanocytes

NASA Astrophysics Data System (ADS)

Narea, J. Freddy; Muñoz, Aarón A.; Castro, Jorge; Muñoz, Rafael A.; Villalba, Caroleny E.; Martinez, María. F.; Bravo, Kelly D.

2013-11-01

Human skin has been studied in numerous investigations, given the interest in knowing information about physiology, morphology and chemical composition. These parameters can be determined using non invasively optical techniques in vivo, such as the diffuse reflectance spectroscopy. The human skin color is determined by many factors, but primarily by the amount and distribution of the pigment melanin. The melanin is produced by the melanocytes in the basal layer of the epidermis. This research characterize the spectral response of the human skin using the coefficients of Fourier series expansion. Simulating the radiative transfer equation for the Monte Carlo method to vary the concentration of the melanocytes (fme) in a simplified model of human skin. It fits relating the Fourier series coefficient a0 with fme. Therefore it is possible to recover the skin biophysical parameter.

[Skin histology and morphometry of the fish Eremophilus mutisii (Trychomecteridae, Siluriformes)].

PubMed

Bonilla Lizarazo, Rocío Johanna; Quintero Virguez, Marllury; Ramírez, Edwin Gómez; Rodríguez Caicedo, Daniel; Hurtado Giraldo, Hermán

2008-06-01

The tropical freshwater fish Eremophylus mutisii is endemic to the Cundinamarca highland in Colombia. Skin samples (0.5x0.5 cm2) were taken from 11 specimens at six body parts (mandible, dorsal head, dorsal trunk, caudal trunk, medial trunk and abdominal area), fixed in 4% formaldehyde, dehydrated in 95% ethanol and 99% isopropanol, embedded in paraffin and sectioned at 5 sm. The skin is made of two mayor cutaneous layers (epidermis and dermis) and a subcutaneous layer (hypodermis). The epidermis presents three layers with secretory cells, epithelial cells and a few taste buds; the dermis is separated from the epidermis by a basal membrane. We observed fibroblasts, two layers of melanophors and some blood vessels; the hypodermis has vascularized adipose tissue. Skin thickness changes with body area; the dermis is thicker than the epidermis; skin has more club cells than mucous cells. The medial trunk area has the largest number of club and mucous cells. The skin of E. mutissi seems to mainly have a protective function.

Epidermal changes in heat and electrically injured pig skin: a light microscopic study of the sequences in morphology.

PubMed

Thomsen, H K; Danielsen, L; Nielsen, O; Aalund, O; Nielsen, K G; Karlsmark, T; Genefke, I K

1982-09-01

Biopsies were obtained from heat and electrically exposed pig skin at different at different times after exposure, in order to describe the morphological sequences in heat and electrically injured skin. The work is part of a series of studies in which it is investigated whether morphological methods can be used in disclosing electrical torture. Epidermal changes in heat lesions differed from those of electrical lesions in all experiments. Heat lesions typically showed a detached epidermis with fibrillar or granular cytoplasm. In older lesions the epidermis appeared concrete. Electrical lesions showed an attached epidermis with small defects, a white, homogeneous cytoplasm, vesicular nuclei and curled, clumped keratin. The electrical lesions were rejected at day 4 or 5. The number of characteristic morphological changes in epidermis decreased with the age of the lesions. It is concluded that epidermal electrical lesions differ in morphology from heat lesions and that it is possible to evaluate the age of the lesions.

Bioinspired Antifreeze Secreting Frost-Responsive Pagophobic Coatings

NASA Astrophysics Data System (ADS)

Sun, Xiaoda; Damle, Viraj; Rykaczewski, Konrad

2014-11-01

Prevention of ice and frost accumulation is of interest to transportation, power generation, and agriculture industries. Superhydrophobic and lubricant impregnated pagophobic coatings have been proposed, however, they both fail in frosting conditions. Inspired by functional liquid secretion in natural systems, such as toxin secretion by poison dart frost in response to predator presence, we developed frost-responsive antifreeze secreting pagophobic coatings. These are bi-layered coatings with an inner superhydrophilic ``dermis'' infused with antifreeze and an outer permeable superhydrophobic ``epidermis.'' The superhydrophobic epidermis separates the antifreeze from the environment and prevents ice accumulation by repelling impinging water droplets. In frosting conditions, the antifreeze is secreted from the dermis through pores in the epidermis either due to contact with condensed droplets or temporary switch of the epidermis wettability from hydrophobic to hydrophilic caused by surface icing. Here we demonstrate superior performance of this multifunctional coating in simulated frosting, freezing mist/fog, and freezing spray/rain conditions. KR acknowledges startup funding from ASU.

The ICAM-3/LFA-1 interaction is critical for epidermal Langerhans cell alloantigen presentation to CD4+ T cells.

PubMed

Griffiths, C E; Railan, D; Gallatin, W M; Cooper, K D

1995-12-01

Intercellular adhesion molecule (ICAM)-3 is a recently described member of the immunoglobulin superfamily and, as such, is closely related to ICAM-1 and ICAM-2. All three ICAMS are cognate for the counter-receptor lymphocyte function associated antigen-1 (LFA-1, CD11a/CD18). Unlike ICAM-1 and ICAM-2, ICAM-3 is constitutively expressed at high levels on resting leucocytes. We investigated the expression and function of ICAM-3 in normal skin (n = 5), as well as its expression in psoriasis (n = 4), atopic eczema (n = 4), allergic (rhus) contact dermatitis (n = 3), and cutaneous T-cell lymphoma (CTCL, n = 2). Five-micrometre cryostat sections of skin were stained using monoclonal antibodies to ICAM-3 and a well characterized immunoperoxidase technique. In normal skin, ICAM-3 was expressed by all cutaneous leucocytes but most striking was the strong expression of ICAM-3 by Langerhans cells within both epidermis and dermis. This observation was confirmed by double-labelling with CD1a and negative staining with an IgG1 isotype control. In psoriasis, atopic eczema, allergic contact dermatitis, and CTCL, ICAM-3 was co-expressed on all CD1a+ cells, although, in psoriasis, the intensity of ICAM-3 expression was reduced. Functional blocking experiments were performed to determine whether the observed ICAM-3 expression on Langerhans cells was functionally important in antigen presentation. CD4+ T cells were prepared from peripheral blood and 10(5) CD4+ T cells combined with 10(5) epidermal cells harvested from keratome biopsies of normal skin of an individual allogeneic to the T-cell donor. Addition of 50 micrograms anti-ICAM-3 to the co-culture resulted in a consistent (50%) reduction in degree of alloantigen presentation by Langerhans cells to T cells. Inhibition was 77% of that produced by the addition of anti-LFA-1. These data indicate that ICAM-3 is constitutively expressed by Langerhans cells and is a major ligand for LFA-1 on CD4+ T cells during their response to Langerhans cells. Because fresh Langerhans cells constitutively express little ICAM-1, whereas ICAM-3 is constitutively expressed at high levels, it would appear that ICAM-3 is the dominant functional ICAM on in situ Langerhans cells in the normal epidermis.

Exposure to acute electromagnetic radiation of mobile phone exposure range alters transiently skin homeostasis of a model of pigmented reconstructed epidermis.

PubMed

Simon, D; Daubos, A; Pain, C; Fitoussi, R; Vié, K; Taieb, A; de Benetti, L; Cario-André, M

2013-02-01

Exposure to electromagnetic radiations (EMR) produced by mobile phone concerns half the world's population and raises the problem of their impact on human health. In this study, we looked at the effects of mobile phone exposure (GSM basic, 900 MHz, SAR 2 mW g(-1) , 6 h) on a model of pigmented skin. We have analysed the expression and localization of various markers of keratinocyte and melanocyte differentiation 2, 6, 18 and 24 h after EMR exposure of reconstructed epidermis containing either only keratinocytes or a combination of keratinocytes and melanocytes grown on dead de-epidermized dermis, using histology, immunohistochemistry and Western blot. No changes were found in epidermal architecture, localization of epidermal markers, presence of apoptotic cells and the induction of p53 in both types of epidermis (with or without melanocytes) after exposure to EMR. In pigmented reconstructs, no change in the location and dendricity of melanocytes and in melanin transfer to neighbouring keratinocytes was detected after EMR exposure. Loricrin, cytokeratin 14 were significantly decreased at 6 h. The level of all markers increased at 24 h as compared to 6 h post-EMR exposure, associated with a significant decrease of the 20S proteasome activity. Our data indicate that exposure to 900 MHz frequency induces a transient alteration of epidermal homoeostasis, which may alter the protective capacity of the skin against external factors. Presence or absence of melanocytes did not modify the behaviour of reconstructs after EMR exposure. © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Accelerated expansion of epidermal keratinocyte and improved dermal reconstruction achieved by engineered amniotic membrane.

PubMed

Huang, Guofeng; Ji, Shizhao; Luo, Pengfei; Liu, Houqi; Zhu, Shihui; Wang, Guangyi; Zhou, Panyu; Xiao, Shichu; Xia, Zhaofan

2013-01-01

In this study, we used human amniotic membrane (AM) to prepare a dermal scaffold with intact basement membrane (BM) and good biostability for quick expansion and transplantation of epidermal keratinocytes (EKs). Fresh AM was treated by repeated freeze-thaw cycles and DNase digestion. This new method was able to cleanse the cell components effectively and retain the BM structure with continuous distributions of laminin, collagen IV, VI, and VII. Subsequently, the acellular amniotic membrane (AAM) was cross-linked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) for 5 min, 30 min, and 6 h. With the time of cross-linking prolonging, the mechanical strength and biostability of AAM increased gradually, while its cytotoxicity to EKs also increased. The 5-min cross-linked AAM (5min-AAM) had no significant cytotoxicity with good histocompatibility. The relative cell viability of EKs seeded on the 5min-AAM surface was 367 ± 33% and 631 ± 43% at 7 and 14 days of culture, respectively, both higher than 294 ± 30% and 503 ± 41% of the conventional cell culture dish (CCD) group, and the proportion of P63-positive cells was significantly higher than that of the CCD group on day 7 (54.32 ± 4.27% vs. 33.32 ± 3.18%, p < 0.05). When the 5min-AAM loaded with EKs (EK-AAM) was grafted onto full-thickness skin defects in nude mice, the cells survived well and formed an epidermis similar to normal skin. The new epidermis was thicker, and reconstruction of the dermal structure was good with an intact BM. Four weeks after transplantation, the wound contraction rate in the EK-AAM group was 43.09 ± 7.05%, significantly lower than that in the EK sheet group (57.49 ± 5.93%) and control group (69.94 ± 9.47%) (p < 0.05). In conclusion, repeated freeze-thaw treatment with appropriate EDC cross-linking offers AAM an intact BM structure with good operability and biostability. It may prove to be an ideal dermal scaffold to promote expansion of EKs in vitro and be transplanted for reconstruction of the dermal structure.

Induction of keratinocyte IL-8 expression and secretion by IgG autoantibodies as a novel mechanism of epidermal neutrophil recruitment in a pemphigus variant

PubMed Central

O'toole, E A; Mak, L L; Guitart, J; Woodley, D T; Hashimoto, T; Amagai, M; Chan, L S

2000-01-01

A subset of pemphigus herpetiformis, a rare pemphigus variant, is characterized histopathologically by subcorneal acantholysis and neutrophilic infiltration. The mechanism of neutrophil infiltration is unknown, but chemokines such as IL-8 may play a role. We investigated the possible role of IL-8 in two such cases. Direct and indirect immunofluorescence studies demonstrated in vivo-bound and circulating IgG epithelial cell surface-binding autoantibodies, both predominated by IgG4 subclass. ELISA and immunoblotting studies revealed that the patients' IgG autoantibodies recognized recombinant desmoglein 1 but not desmoglein 3. Preadsorption of the patients' sera with recombinant desmoglein 1 completely removed the epidermal cell surface immunostaining. Significantly, immunohistochemistry demonstrated intense expression of IL-8, co-localized with in vivo-bound IgG, in the upper epidermis, where the acantholysis took place. Affinity-purified sera IgG from these two patients, a normal individual, and a pemphigus vulgaris patient containing desmoglein 1 autoantibodies, were incubated with normal human keratinocytes in vitro. Cells treated with these patients' IgG secreted a seven-to-nine-fold increase of IL-8 (30–37 pg/ml) compared with the controls (2–4 pg/ml) and expressed a higher intensity of cytoplasmic IL-8 staining. These data demonstrate a novel functional role for IL-8 in the pathogenesis of the neutrophil-dominant subset of pemphigus herpetiformis. The autoantibody-induced epidermal cell IL-8 expression may represent a novel mechanism of epidermal neutrophil recruitment. PMID:10606986

A novel method of measuring leaf epidermis and mesophyll stiffness shows the ubiquitous nature of the sandwich structure of leaf laminas in broad-leaved angiosperm species

PubMed Central

Onoda, Yusuke; Schieving, Feike; Anten, Niels P. R.

2015-01-01

Plant leaves commonly exhibit a thin, flat structure that facilitates a high light interception per unit mass, but may increase risks of mechanical failure when subjected to gravity, wind and herbivory as well as other stresses. Leaf laminas are composed of thin epidermis layers and thicker intervening mesophyll layers, which resemble a composite material, i.e. sandwich structure, used in engineering constructions (e.g. airplane wings) where high bending stiffness with minimum weight is important. Yet, to what extent leaf laminas are mechanically designed and behave as a sandwich structure remains unclear. To resolve this issue, we developed and applied a novel method to estimate stiffness of epidermis- and mesophyll layers without separating the layers. Across a phylogenetically diverse range of 36 angiosperm species, the estimated Young’s moduli (a measure of stiffness) of mesophyll layers were much lower than those of the epidermis layers, indicating that leaf laminas behaved similarly to efficient sandwich structures. The stiffness of epidermis layers was higher in evergreen species than in deciduous species, and strongly associated with cuticle thickness. The ubiquitous nature of sandwich structures in leaves across studied species suggests that the sandwich structure has evolutionary advantages as it enables leaves to be simultaneously thin and flat, efficiently capturing light and maintaining mechanical stability under various stresses. PMID:25675956

A Common Position-Dependent Mechanism Controls Cell-Type Patterning and GLABRA2 Regulation in the Root and Hypocotyl Epidermis of Arabidopsis1

PubMed Central

Hung, Chen-Yi; Lin, Yan; Zhang, Meng; Pollock, Susan; David Marks, M.; Schiefelbein, John

1998-01-01

A position-dependent pattern of epidermal cell types is produced during root development in Arabidopsis thaliana. This pattern is reflected in the expression pattern of GLABRA2 (GL2), a homeobox gene that regulates cell differentiation in the root epidermis. GL2 promoter::GUS fusions were used to show that the TTG gene, a regulator of root epidermis development, is necessary for maximal GL2 activity but is not required for the pattern of GL2 expression. Furthermore, GL2-promoter activity is influenced by expression of the myc-like maize R gene (35S::R) in Arabidopsis but is not affected by gl2 mutations. A position-dependent pattern of cell differentiation and GL2-promoter activity was also discovered in the hypocotyl epidermis that was analogous to the pattern in the root. Non-GL2-expressing cell files in the hypocotyl epidermis located outside anticlinal cortical cell walls exhibit reduced cell length and form stomata. Like the root, the hypocotyl GL2 activity was shown to be influenced by ttg and 35S::R but not by gl2. The parallel pattern of cell differentiation in the root and hypocotyl indicates that TTG and GL2 participate in a common position-dependent mechanism to control cell-type patterning throughout the apical-basal axis of the Arabidopsis seedling. PMID:9576776

In vivo histological evaluation of non-insulated microneedle radiofrequency applicator with novel fractionated pulse mode.

PubMed

Harth, Yoram; Frank, Ido

2013-12-01

Microneedle radiofrequency is a novel method that allows non-thermal penetration of the epidermis followed by RF coagulation in selected depth of the dermis surrounded by zone of non-coagulative volumetric heating. The first generation of Microneedle RF applicators used insulated needles. These treatments were limited by a few factors, including low volume of dermal heating, lack of effect in the papillary dermis and pinpoint bleeding during the treatment. The system tested in this study (EndyMed PRO, Intensif applicator, EndyMed Medical, Cesarea, Israel) utilizes special extra sharp tapered non-insulated microneedles and a special pulse mode, allowing full coagulation during treatment and higher effective volume of dermal heat. After Ethics Committee approval, one female pig (Type Large white X Landrace, 34 Kg) was chosen for the study. The animal was anesthetized using Ketamine, Xylazin and Isofluran. The EndyMed PRO, Intensif applicator (was used for treatment with different needle depth penetration (1 mm-3.5 mm) and in multiple energy settings. Six mm punch biopsies were harvested for histological analysis at the following time points: immediately after the treatment, 4 days after the treatment and 14 days after the treatment. H&E and Masson-Trichrome stains were processed. Visual inspection of the treated skin, immediately after the treatment, revealed arrays of pinpoint erythematous papules surrounded by undamaged epidermal tissue. Treatment field showed no sign of bleeding. Mild to moderate Erythema and Edema developed a few minutes after the treatment, varying according to the total energy delivered. The histologies taken 4-day after therapy showed in all energy settings, dry micro crusts over the treatment zones, with full healing of epidermis. In the 14-day specimens there was a replacement of the crusts/debris by a normal looking stratum corneum with complete healing of epidermis and dermis. The current in vivo study confirms that the EndyMed PRO Intensif applicator effective and predictable tool to create cylindrical micro zones of coagulation in the papillary and reticular dermis with minimal damage to the epidermis. The histologies taken 4 days and 14 days after treatment show rapid epidermal renewal with predictable volume of coagulation in dermis related to the length of the needle and the power used. Coagulation of capillaries during treatment allows a dry treatment field. The predictability of the effect and minimal downtime may offer a significant advantage over treatments with ablative fractional lasers of insulated RF microneedles.

Water Buffalo (Bubalus bubalis) as a spontaneous animal model of Vitiligo.

PubMed

Singh, Vijay Pal; Motiani, Rajender K; Singh, Archana; Malik, Garima; Aggarwal, Rangoli; Pratap, Kunal; Wani, Mohan R; Gokhale, Suresh B; Natarajan, Vivek T; Gokhale, Rajesh S

2016-07-01

Vitiligo is a multifactorial acquired depigmenting disorder. Recent insights into the molecular mechanisms driving the gradual destruction of melanocytes in vitiligo will likely lead to the discovery of novel therapies, which need to be evaluated in animal models that closely recapitulate the pathogenesis of human vitiligo. In humans, vitiligo is characterized by a spontaneous loss of functional melanocytes from the epidermis, but most animal models of vitiligo are either inducible or genetically programmed. Here, we report that acquired depigmentation in water buffalo recapitulates molecular, histological, immunohistochemical, and ultrastructural changes observed in human vitiligo and hence could be used as a model to study vitiligo pathogenesis and facilitate the discovery and evaluation of therapeutic interventions for vitiligo. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Glycophenotype Evaluation in Cutaneous Tumors Using Lectins Labeled with Acridinium Ester

PubMed Central

Lima, Luiza Rayanna Amorim; Almeida, Sinara Mônica Vitalino; Silva, Lúcia Patrícia Bezerra Gomes; Beltrão, Eduardo Isidoro Carneiro; Carvalho Júnior, Luiz Bezerra

2013-01-01

Background. Tumor cells show alterations in their glycosylation patterns when compared to normal cells. Lectins can be used to evaluate these glycocode changes. Chemiluminescence assay is an effective technique for quantitative analysis of proteins, nucleic acids, and carbohydrates due to its high sensitivity, specificity, and rapid testing. Objective. To use histochemiluminescence based on lectin conjugated to acridinium ester (AE) for the investigation of glycophenotype changes in cutaneous tumors. Methods. Concanavalin A (Con A), Peanut agglutinin (PNA), Ulex europaeus agglutinin-I (UEA-I), and Maackia amurensis agglutinin (MAA) were conjugated to acridinium ester. Biopsies of cutaneous tumors and normal skin were incubated with the lectins-AE, and chemiluminescence was quantified and expressed as Relative Light Units (RLU). Results. Actinic keratosis (AK), keratoacanthoma (KA), squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) showed lower expression of α-D-glucose/mannose and α-L-fucose residues compared to normal tissue. Cutaneous tumors displayed higher expression of Gal-β(1-3)-GalNAc residues than normal tissue. AK and SCC exhibited higher expression of Neu5Ac-α(2,3)Gal residues than normal epidermis. KA and BCC showed equivalent RLU values compared to normal tissue. Conclusions. Lectin histochemiluminescence allowed quantitative assessment of the carbohydrate expression in cutaneous tissues, contributing to eliminate the subjectivity of conventional techniques used in the histopathological diagnosis. PMID:24167360

Intelligent Tutoring Systems: Machine Learning Research

DTIC Science & Technology

1991-07-01

is composed of cutin . Ki: Cutin is impermeable to gases. Does the cuticle restrict water loss from the leaf? Domain Expert: Yes, that’s right. Kl...transported from inside the Leaf Epidermis to the atmosphere outside of the Leaf Epidermis. Rule 1: If an object is composed of cutin , then it is

Ethnic variation in melanin content and composition in photoexposed and photoprotected human skin.

PubMed

Alaluf, Simon; Atkins, Derek; Barrett, Karen; Blount, Margaret; Carter, Nik; Heath, Alan

2002-04-01

We have examined the quantity and composition of melanin in both photoprotected (volar upper arm) and chronically photoexposed (dorsal forearm) skin from a range of different ethnic skin types including African, Indian, Mexican, Chinese and European. The most lightly pigmented (European, Chinese and Mexican) skin types have approximately half as much epidermal melanin as the most darkly pigmented (African and Indian) skin types. However, the composition of melanin in these lighter skin types is comparatively more enriched with lightly coloured, alkali-soluble melanin components (up to three-fold). Regardless of ethnicity, epidermal melanin content is significantly greater in chronically photoexposed skin than it is in corresponding photoprotected skin (up to two-fold). However, by comparison there is only a modest enrichment of lightly coloured, alkali soluble melanin components in photoprotected skin (up to 1.3-fold). Analysis of melanosomes extracted from the epidermis in these subjects indicates that the proportion of spheroidal melanosomes is low in all skin types examined (<10%). This suggests that in human skin, pheomelanin is a very minor component of epidermal melanin, even in the lightest (European) skin types. Analysis of melanosome size revealed a significant and progressive variation in size with ethnicity: African skin having the largest melanosomes followed in turn by Indian, Mexican, Chinese and European. On the basis of these findings, we propose that variation in skin pigmentation is strongly influenced by both the amount and the composition (or colour) of the melanin in the epidermis. Variation in melanosome size may also play a significant role. However, the data also suggest that in human skin there are subtle differences in the mechanisms associated with the maintenance of constitutive pigmentation and facultative hyperpigmentation, respectively.

Interleukin-32 promotes detachment and activation of human Langerhans cells in a human skin explant model.

PubMed

Gonnet, J; Perrin, H; Hutton, A J; Boccara, D; Bonduelle, O; Mimoun, M; Atlan, M; Soria, A; Combadière, B

2018-05-28

Cross-talk between skin keratinocytes (KCs) and Langerhans cells (LCs) plays a fundamental role in the body's first line of immunological defences. However, the mechanism behind the interaction between these two major epidermal cells is unknown. Interleukin (IL)-32 is produced in inflammatory skin disorders. We questioned the role of IL-32 in the epidermis. We aimed to determine the role of IL-32 produced by KCs on surrounding LCs. We used an ex vivo human explant model from healthy donors and investigated the role of IL-32 on LC activation using imaging, flow cytometry, reverse transcriptase quantitative polymerase chain reaction and small interfering (si)RNA treatment. Modified vaccinia virus ankara (MVA) infection induced KC death alongside the early production of the proinflammatory cytokine IL-32. We demonstrated that IL-32 produced by MVA-infected KCs induced modest but significant morphological changes in LCs and downregulation of adhesion molecules, such as epithelial cell adhesion molecule and very late antigen-4, and CXCL10 production. The treatment of KCs with IL-32-specific siRNA, and anti-IL-32 blocking antibody significantly inhibited LC activation, demonstrating the role of IL-32 in LC activation. We also found that some Toll-like receptor ligands induced a very high level of IL-32 production by KCs, which initiated LC activation. We propose, for the first time, that IL-32 is a molecular link between KCs and LCs in healthy skin, provoking LC migration from the epidermis to the dermis prior to their migration to the draining lymph nodes. © 2018 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.

The effects of IL-20 subfamily cytokines on reconstituted human epidermis suggest potential roles in cutaneous innate defense and pathogenic adaptive immunity in psoriasis.

PubMed

Sa, Susan M; Valdez, Patricia A; Wu, Jianfeng; Jung, Kenneth; Zhong, Fiona; Hall, Linda; Kasman, Ian; Winer, Jane; Modrusan, Zora; Danilenko, Dimitry M; Ouyang, Wenjun

2007-02-15

IL-19, IL-20, IL-22, IL-24, and IL-26 are members of the IL-10 family of cytokines that have been shown to be up-regulated in psoriatic skin. Contrary to IL-10, these cytokines signal using receptor complex R1 subunits that are preferentially expressed on cells of epithelial origin; thus, we henceforth refer to them as the IL-20 subfamily cytokines. In this study, we show that primary human keratinocytes (KCs) express receptors for these cytokines and that IL-19, IL-20, IL-22, and IL-24 induce acanthosis in reconstituted human epidermis (RHE) in a dose-dependent manner. These cytokines also induce expression of the psoriasis-associated protein S100A7 and keratin 16 in RHE and cause persistent activation of Stat3 with nuclear localization. IL-22 had the most pronounced effects on KC proliferation and on the differentiation of KCs in RHE, inducing a decrease in the granular cell layer (hypogranulosis). Furthermore, gene expression analysis performed on cultured RHE treated with these cytokines showed that IL-19, IL-20, IL-22, and IL-24 regulate many of these same genes to variable degrees, inducing a gene expression profile consistent with inflammatory responses, wound healing re-epithelialization, and altered differentiation. Many of these genes have also been found to be up-regulated in psoriatic skin, including several chemokines, beta-defensins, S100 family proteins, and kallikreins. These results confirm that IL-20 subfamily cytokines are important regulators of epidermal KC biology with potentially pivotal roles in the immunopathology of psoriasis.

Disinfection and healing effects of 222-nm UVC light on methicillin-resistant Staphylococcus aureus infection in mouse wounds.

PubMed

Narita, Kouji; Asano, Krisana; Morimoto, Yukihiro; Igarashi, Tatsushi; Hamblin, Michael R; Dai, Tianhong; Nakane, Akio

2018-01-01

UVC radiation is known to be highly germicidal. However, exposure to 254-nm-UVC light causes DNA lesions such as cyclobutane pyrimidine dimers (CPD) in human cells, and can induce skin cancer after long-term repeated exposures. It has been reported that short wavelength UVC is absorbed by proteins in the membrane and cytosol, and fails to reach the nucleus of human cells. Hence, irradiation with 222-nm UVC might be an optimum combination of effective disinfection and biological safety to human cells. In this study, the biological effectiveness of 222-nm UVC was investigated using a mouse model of a skin wound infected with methicillin-resistant Staphylococcus aureus (MRSA). Irradiation with 222-nm UVC significantly reduced bacterial numbers on the skin surface compared with non-irradiated skin. Bacterial counts in wounds evaluated on days 3, 5, 8 and 12 after irradiation demonstrated that the bactericidal effect of 222-nm UVC was equal to or more effective than 254-nm UVC. Histological analysis revealed that migration of keratinocytes which is essential for the wound healing process was impaired in wounds irradiated with 254-nm UVC, but was unaffected in 222-nm UVC irradiated wounds. No CPD-expressing cells were detected in either epidermis or dermis of wounds irradiated with 222-nm UVC, whereas CPD-expressing cells were found in both epidermis and dermis irradiation with 254-nm UVC. These results suggest that 222-nm UVC light may be a safe and effective way to reduce the rate of surgical site and other wound infections. Copyright © 2017 Elsevier B.V. All rights reserved.

N-Acetylglutaminoyl-S-farnesyl-L-cysteine (SIG-1191): an anti-inflammatory molecule that increases the expression of the aquaglyceroporin, aquaporin-3, in human keratinocytes.

PubMed

Fernández, José R; Webb, Corey; Rouzard, Karl; Voronkov, Michael; Huber, Kristen L; Stock, Jeffry B; Stock, Maxwell; Gordon, Joel S; Perez, Eduardo

2017-03-01

Isoprenylcysteine (IPC) small molecules were discovered as signal transduction modulating compounds ~25 years ago. More recently, IPC molecules have demonstrated antioxidant and anti-inflammatory properties in a variety of dermal cells as well as antimicrobial activity, representing a novel class of compounds to ameliorate skin conditions and disease. Here, we demonstrate a new IPC compound, N-acetylglutaminoyl-S-farnesyl-L-cysteine (SIG-1191), which inhibits UVB-induced inflammation blocking pro-inflammatory cytokine interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) production. To investigate further the previously reported hydrating potential of IPC compounds, SIG-1191 was tested for its ability to modulate aquaporin expression. Specifically, aquaporin 3 (AQP3) the most abundant aquaporin found in skin has been reported to play a key role in skin hydration, elasticity and barrier repair. Results show here for the first time that SIG-1191 increases AQP3 expression in both cultured normal human epidermal keratinocytes as well as when applied topically in a three-dimensional (3D) reconstructed human skin equivalent. Additionally, SIG-1191 dose dependently increased AQP3 protein levels, as determined by specific antibody staining, in the epidermis of the 3D skin equivalents. To begin to elucidate which signaling pathways SIG-1191 may be modulating to increase AQP3 levels, we used several pharmacological pathway inhibitors and determined that AQP3 expression is mediated by the Mitogen-activated protein kinase/Extracellular signal-regulated kinase kinase (MEK) pathway. Altogether, these data suggest SIG-1191 represents a new IPC derivative with anti-inflammatory activity that may also promote increased skin hydration based on its ability to increase AQP3 levels.

Cold flow of estradiol transdermal systems: influence of drug loss on the in vitro flux and drug transfer across human epidermis.

PubMed

Krishnaiah, Yellela S R; Yang, Yang; Hunt, Robert L; Khan, Mansoor A

2014-12-30

The objective was to quantify drug loss due to cold flow (CF) in marketed estradiol transdermal drug delivery systems (TDDS), and study its influence on the in vitro flux and drug transfer across contacting skin. TDDS samples (products-A and B) were induced with CF at 25 and 32°C/60% RH by applying 1-kg force for 72h. CF was measured as percent dimensional change and amount of drug loss/migration in CF region. In vitro drug permeation studies were conducted across human epidermis from TDDS excluding CF region, and CF region alone against control (without CF). In both products, significantly higher percentage of CF (dimensional change and drug migration) was observed at 32°C compared to 25°C. In vitro flux from both products excluding CF region either at 25 or 32°C was the same, but significantly lower compared to control. Drug transferred from CF region of product-A after 8h was the same at 25 and 32°C, but significantly higher in product-B. Flux from both products together with CF region at 32°C was significantly lower than that observed at 25°C. Results showed that excessive CF at storage (25°C) and clinical usage (32°C) conditions may have implications on product performance and safety of estradiol TDDS. Published by Elsevier B.V.

Epidermal protection with cryogen spray cooling during high fluence pulsed dye laser irradiation: an ex vivo study.

PubMed

Tunnell, J W; Nelson, J S; Torres, J H; Anvari, B

2000-01-01

Higher laser fluences than currently used in therapy (5-10 J/cm(2)) are expected to result in more effective treatment of port wine stain (PWS) birthmarks. However, higher incident fluences increase the risk of epidermal damage caused by absorption of light by melanin. Cryogen spray cooling offers an effective method to reduce epidermal injury during laser irradiation. The objective of this study was to determine whether high laser incident fluences (15-30 J/cm(2)) could be used while still protecting the epidermis in ex vivo human skin samples. Non-PWS skin from a human cadaver was irradiated with a Candela ScleroPlus Laser (lambda = 585 nm; pulse duration = 1.5 msec) by using various incident fluences (8-30 J/cm(2)) without and with cryogen spray cooling (refrigerant R-134a; spurt durations: 40-250 msec). Assessment of epidermal damage was based on histologic analysis. Relatively short spurt durations (40-100 msec) protected the epidermis for laser incident fluences comparable to current therapeutic levels (8-10 J/cm(2)). However, longer spurt durations (100-250 msec) increased the fluence threshold for epidermal damage by a factor of three (up to 30 J/cm(2)) in these ex vivo samples. Results of this ex vivo study show that epidermal protection from high laser incident fluences can be achieved by increasing the cryogen spurt duration immediately before pulsed laser exposure. Copyright 2000 Wiley-Liss, Inc.

Diffusion profile of macromolecules within and between human skin layers for (trans)dermal drug delivery.

PubMed

Römgens, Anne M; Bader, Dan L; Bouwstra, Joke A; Baaijens, Frank P T; Oomens, Cees W J

2015-10-01

Delivering a drug into and through the skin is of interest as the skin can act as an alternative drug administration route for oral delivery. The development of new delivery methods, such as microneedles, makes it possible to not only deliver small molecules into the skin, which are able to pass the outer layer of the skin in therapeutic amounts, but also macromolecules. To provide insight into the administration of these molecules into the skin, the aim of this study was to assess the transport of macromolecules within and between its various layers. The diffusion coefficients in the epidermis and several locations in the papillary and reticular dermis were determined for fluorescein dextran of 40 and 500 kDa using a combination of fluorescent recovery after photobleaching experiments and finite element analysis. The diffusion coefficient was significantly higher for 40 kDa than 500 kDa dextran, with median values of 23 and 9 µm(2)/s in the dermis, respectively. The values only marginally varied within and between papillary and reticular dermis. For the 40 kDa dextran, the diffusion coefficient in the epidermis was twice as low as in the dermis layers. The adopted method may be used for other macromolecules, which are of interest for dermal and transdermal drug delivery. The knowledge about diffusion in the skin is useful to optimize (trans)dermal drug delivery systems to target specific layers or cells in the human skin. Copyright © 2015 Elsevier Ltd. All rights reserved.

Barrier Requirements as the Evolutionary “Driver” of Epidermal Pigmentation in Humans

PubMed Central

ELIAS, PETER M.; MENON, GOPINATHAN; WETZEL, BRUCE K.; WILLIAMS, JOHN (JACK) W.

2011-01-01

Current explanations for the development of epidermal pigmentation during human evolution are not tenable as stand-alone hypotheses. Accordingly, we assessed instead whether xeric- and UV-B-induced stress to the epidermal permeability barrier, critical to survival in a terrestrial environment, could have “driven” the development of epidermal pigmentation. (1) Megadroughts prevailed in central Africa when hominids expanded into open savannahs [≈1.5–0.8 million years ago], resulting in sustained exposure to both extreme aridity and erythemogenic UV-B, correlating with genetic evidence that pigment developed ≈1.2 million years ago. (2) Pigmented skin is endowed with enhanced permeability barrier function, stratum corneum integrity/cohesion, and a reduced susceptibility to infections. The enhanced function of pigmented skin can be attributed to the lower pH of the outer epidermis, likely due to the persistence of (more-acidic) melanosomes into the outer epidermis, as well as the conservation of genes associated with eumelanin synthesis and melanosome acidification (e.g., TYR, OCA2 [p protein], SLC24A5, SLC45A2, MATP) in pigmented populations. Five keratinocyte-derived signals (stem cell factor⇒KIT; FOXn1⇒FGF2; IL-1α, NGF, and p53) are potential candidates to have stimulated the sequential development of epidermal pigmentation in response to stress to the barrier. We summarize evidence here that epidermal interfollicular pigmentation in early hominids likely evolved in response to stress to the permeability barrier. PMID:20209486

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Sun Hee; Choi, Dalwoong; Chun, Young-Jin

Keratinocytes are the major cellular components of human epidermis and play a key role in the modulating cutaneous inflammation and toxic responses. In human chronic skin diseases, the common skin inflammatory phenotypes like skin barrier disruption and epidermal hyperplasia are manifested in epidermal keratinocytes by interactions with T helper (Th) cells. To find a common gene expression signature of human keratinocytes in chronic skin diseases, we performed a whole genome microarray analysis on normal human epidermal keratinocytes (NHKs) treated with IFNγ, IL-4, IL-17A or IL-22, major cytokines from Th1, Th2, Th17 or Th22 cells, respectively. The microarray results showed thatmore » the four genes, IL-24, PDZK1IP1, H19 and filaggrin, had common expression profiles in NHKs exposed to Th cell cytokines. In addition, the acute phase pro-inflammatory cytokines, IL-1β, IL-6 and TNFα, also change the gene transcriptional profile of IL-24, PDZK1IP1, H19, and filaggrin in NHKs as those of Th cytokines. Therefore, the signature gene set, consisting of IL-24, PDZK1IP1, H19, and filaggrin, provides essential insights for understanding the process of cutaneous inflammation and toxic responses. We demonstrate that environmental toxic stressors, such as chemical irritants and ultraviolet irradiation stimulate the production of IL-24 in NHKs. IL-24 stimulates the JAK1-STAT3 and MAPK pathways in NHKs, and promotes the secretion of pro-inflammatory mediators IL-8, PGE2, and MMP-1. These results suggest that keratinocyte-derived IL-24 participates in the positive feedback regulation of epidermal inflammation in response to both endogenous and environmental toxic stressors. - Highlights: • Cutaneous inflammatory gene signature consists of PDZK1IP1, IL-24, H19 and filaggrin. • Pro-inflammatory cytokines increase IL-24 production in human keratinocytes. • Environmental toxic stressors increase IL-24 production in human keratinocytes. • IL-24 stimulates human keratinocytes to produce pro-inflammatory mediators. • IL-24 activates STAT3 and MAPK signaling pathways in human keratinocytes.« less

Oral supplementation of Lithospermum erythrorhizon prevents the development of atopic dermatitis with reducing ceramide degradation in the epidermis of NC/Nga mice.

PubMed

Kim, JungMin; Kim, YoungRan; Seo, DaeBang; Kim, SungHan; Lee, SangJun; Cho, Yunhi

2009-09-01

Lithospermum erythrorhizon Sieb. et Zucc. (LE) is widely used in the treatment of abnormal skin conditions, but its systemic efficacy, especially in atopic dermatitis (AD), is not clear. To examine the systemic efficacy of LE on the clinical manifestation of AD-like skin lesions, NC/Nga mice, a murine model of AD, were fed a control diet (group CA: atopic control) or a diet with a 70% ethanol extract from 5% LE (group LE) for 10 weeks. In group LE, the clinical manifestation of AD-like skin lesions was prevented as the level of serum IgE, epidermal hyperproliferation, and the number and duration of scratching episodes, which were greater in group CA, were significantly reduced to a similar level of the normal control group of BALB/c mice (group C). In addition, the level of ceramides, the major lipid maintaining the epidermal barrier, in the epidermis of group LE was increased, and was inversely associated with a decreased protein level of ceramidase, an enzyme of ceramide degradation. However, the mRNA and the protein levels of serine palmitoyl transferase (enzyme for de novo ceramide synthesis) in groups C, CA and LE did not differ. It was demonstrated that oral supplementation with LE extract prevented the development of atopic dermatitis with reducing ceramide degradation coupled with a low expression of ceramidase protein.

Delineation of Matriptase Protein Expression by Enzymatic Gene Trapping Suggests Diverging Roles in Barrier Function, Hair Formation, and Squamous Cell Carcinogenesis

PubMed Central

List, Karin; Szabo, Roman; Molinolo, Alfredo; Nielsen, Boye Schnack; Bugge, Thomas H.

2006-01-01

The membrane serine protease matriptase is required for epidermal barrier function, hair formation, and thymocyte development in mice, and dysregulated matriptase expression causes epidermal squamous cell carcinoma. To elucidate the specific functions of matriptase in normal and aberrant epidermal differentiation, we used enzymatic gene trapping combined with immunohistochemical, ultrastructural, and barrier function assays to delineate the spatio-temporal expression and function of matriptase in mouse keratinized tissue development, homeostasis, and malignant transformation. In the interfollicular epidermis, matriptase expression was restricted to postmitotic transitional layer keratinocytes undergoing terminal differentiation. Matriptase was also expressed in keratinizing oral epithelium, where it was required for oral barrier function, and in thymic epithelium. In all three tissues, matriptase colocalized with profilaggrin. In staged embryos, the onset of epidermal matriptase expression coincided with that of profilaggrin expression and acquisition of the epidermal barrier. In marked contrast to stratifying keritinized epithelium, matripase expression commenced already in undifferentiated and rapidly proliferating profilaggrin-negative matrix cells and displayed hair growth cycle-dependent expression. Exposure of the epidermis to carcinogens led to the gradual appearance of matriptase in a keratin-5-positive proliferative cell compartment during malignant progression. Combined with previous studies, these data suggest that matriptase has diverging functions in the genesis of stratified keratinized epithelium, hair follicles, and squamous cell carcinoma. PMID:16651618

Delineation of matriptase protein expression by enzymatic gene trapping suggests diverging roles in barrier function, hair formation, and squamous cell carcinogenesis.

PubMed

List, Karin; Szabo, Roman; Molinolo, Alfredo; Nielsen, Boye Schnack; Bugge, Thomas H

2006-05-01

The membrane serine protease matriptase is required for epidermal barrier function, hair formation, and thymocyte development in mice, and dysregulated matriptase expression causes epidermal squamous cell carcinoma. To elucidate the specific functions of matriptase in normal and aberrant epidermal differentiation, we used enzymatic gene trapping combined with immunohistochemical, ultrastructural, and barrier function assays to delineate the spatio-temporal expression and function of matriptase in mouse keratinized tissue development, homeostasis, and malignant transformation. In the interfollicular epidermis, matriptase expression was restricted to postmitotic transitional layer keratinocytes undergoing terminal differentiation. Matriptase was also expressed in keratinizing oral epithelium, where it was required for oral barrier function, and in thymic epithelium. In all three tissues, matriptase colocalized with profilaggrin. In staged embryos, the onset of epidermal matriptase expression coincided with that of profilaggrin expression and acquisition of the epidermal barrier. In marked contrast to stratifying keritinized epithelium, matripase expression commenced already in undifferentiated and rapidly proliferating profilaggrin-negative matrix cells and displayed hair growth cycle-dependent expression. Exposure of the epidermis to carcinogens led to the gradual appearance of matriptase in a keratin-5-positive proliferative cell compartment during malignant progression. Combined with previous studies, these data suggest that matriptase has diverging functions in the genesis of stratified keratinized epithelium, hair follicles, and squamous cell carcinoma.

A multitechnique evaluation of topical corticosteroid treatment.

PubMed

Josse, G; Rouvrais, C; Mas, A; Haftek, M; Delalleau, A; Ferraq, Y; Ossant, F; George, J; Lagarde, J M; Schmitt, A M

2009-02-01

Corticosteroids are widely prescribed for systemic or local treatment of inflammatory autoimmune disorders. Long-term therapy is associated with side effects and causes cutaneous atrophy of the epidermis and the dermis. The present study aims to evaluate with several noninvasive techniques, the skin modifications observed during corticosteroids treatment. The potential of skin mechanical measurement and ultrasound radio frequency (RF) signal analysis are proposed as new measures more closely related to the functional impairments. Thirteen young healthy women volunteers had two applications per day on one arm of topical Clobetasol propionate 0.05% for 28 days, and they were followed for 28 days more. Skin modifications were studied by high-frequency ultrasound imaging, ultrasound RF signal analysis, optical coherence tomography and by the suction test. For all the techniques, a statistically significant change is observed with treatment. Large variations, around 30%, are observed for all techniques, but less for ultrasound imaging (10%). Dermis and epidermis thickness presented stable measurements on the nontreated zone. At the end of the study, measures returned to normal. The dynamic is mainly observed within the first 14 days of treatment and within the first 14 days after its cessation. Similar dynamics of skin modification during corticosteroid treatment was observed with very different techniques. Moreover, the potential of RF ultrasound analysis and mechanical skin measurement for characterizing skin structural and functional impairments has been evaluated.

Skin appendage-derived stem cells: cell biology and potential for wound repair.

PubMed

Xie, Jiangfan; Yao, Bin; Han, Yutong; Huang, Sha; Fu, Xiaobing

2016-01-01

Stem cells residing in the epidermis and skin appendages are imperative for skin homeostasis and regeneration. These stem cells also participate in the repair of the epidermis after injuries, inducing restoration of tissue integrity and function of damaged tissue. Unlike epidermis-derived stem cells, comprehensive knowledge about skin appendage-derived stem cells remains limited. In this review, we summarize the current knowledge of skin appendage-derived stem cells, including their fundamental characteristics, their preferentially expressed biomarkers, and their potential contribution involved in wound repair. Finally, we will also discuss current strategies, future applications, and limitations of these stem cells, attempting to provide some perspectives on optimizing the available therapy in cutaneous repair and regeneration.

Intercellular crosstalk in human malignant melanoma.

PubMed

Dvořánková, Barbora; Szabo, Pavol; Kodet, Ondřej; Strnad, Hynek; Kolář, Michal; Lacina, Lukáš; Krejčí, Eliška; Naňka, Ondřej; Šedo, Aleksi; Smetana, Karel

2017-05-01

Incidence of malignant melanoma is increasing globally. While the initial stages of tumors can be easily treated by a simple surgery, the therapy of advanced stages is rather limited. Melanoma cells spread rapidly through the body of a patient to form multiple metastases. Consequently, the survival rate is poor. Therefore, emphasis in melanoma research is given on early diagnosis and development of novel and more potent therapeutic options. The malignant melanoma is arising from melanocytes, cells protecting mitotically active keratinocytes against damage caused by UV light irradiation. The melanocytes originate in the neural crest and consequently migrate to the epidermis. The relationship between the melanoma cells, the melanocytes, and neural crest stem cells manifests when the melanoma cells are implanted to an early embryo: they use similar migratory routes as the normal neural crest cells. Moreover, malignant potential of these melanoma cells is overdriven in this experimental model, probably due to microenvironmental reprogramming. This observation demonstrates the crucial role of the microenvironment in melanoma biology. Indeed, malignant tumors in general represent complex ecosystems, where multiple cell types influence the growth of genetically mutated cancer cells. This concept is directly applicable to the malignant melanoma. Our review article focuses on possible strategies to modify the intercellular crosstalk in melanoma that can be employed for therapeutic purposes.

Impaired epithelial differentiation of induced pluripotent stem cells from ectodermal dysplasia-related patients is rescued by the small compound APR-246/PRIMA-1MET.

PubMed

Shalom-Feuerstein, Ruby; Serror, Laura; Aberdam, Edith; Müller, Franz-Josef; van Bokhoven, Hans; Wiman, Klas G; Zhou, Huiqing; Aberdam, Daniel; Petit, Isabelle

2013-02-05

Ectodermal dysplasia is a group of congenital syndromes affecting a variety of ectodermal derivatives. Among them, ectrodactyly, ectodermal dysplasia, and cleft lip/palate (EEC) syndrome is caused by single point mutations in the p63 gene, which controls epidermal development and homeostasis. Phenotypic defects of the EEC syndrome include skin defects and limbal stem-cell deficiency. In this study, we designed a unique cellular model that recapitulated major embryonic defects related to EEC. Fibroblasts from healthy donors and EEC patients carrying two different point mutations in the DNA binding domain of p63 were reprogrammed into induced pluripotent stem cell (iPSC) lines. EEC-iPSC from both patients showed early ectodermal commitment into K18(+) cells but failed to further differentiate into K14(+) cells (epidermis/limbus) or K3/K12(+) cells (corneal epithelium). APR-246 (PRIMA-1(MET)), a small compound that restores functionality of mutant p53 in human tumor cells, could revert corneal epithelial lineage commitment and reinstate a normal p63-related signaling pathway. This study illustrates the relevance of iPSC for p63 related disorders and paves the way for future therapy of EEC.

Topical Application of Trisodium Ascorbyl 6-Palmitate 2-Phosphate Actively Supplies Ascorbate to Skin Cells in an Ascorbate Transporter-Independent Manner

PubMed Central

Shibuya, Shuichi; Sakaguchi, Ikuyo; Ito, Shintaro; Kato, Eiko; Watanabe, Kenji; Izuo, Naotaka; Shimizu, Takahiko

2017-01-01

Ascorbic acid (AA) possesses multiple beneficial functions, such as regulating collagen biosynthesis and redox balance in the skin. AA derivatives have been developed to overcome this compound’s high fragility and to assist with AA supplementation to the skin. However, how AA derivatives are transferred into cells and converted to AA in the skin remains unclear. In the present study, we showed that AA treatment failed to increase the cellular AA level in the presence of AA transporter inhibitors, indicating an AA transporter-dependent action. In contrast, torisodium ascorbyl 6-palmitate 2-phosphate (APPS) treatment significantly enhanced the cellular AA level in skin cells despite the presence of inhibitors. In ex vivo experiments, APPS treatment also increased the AA content in a human epidermis model. Interestingly, APPS was readily metabolized and converted to AA in keratinocyte lysates via an intrinsic mechanism. Furthermore, APPS markedly repressed the intracellular superoxide generation and promoted viability associated with an enhanced AA level in Sod1-deficient skin cells. These findings indicate that APPS effectively restores the AA level and normalizes the redox balance in skin cells in an AA transporter-independent manner. Topical treatment of APPS is a beneficial strategy for supplying AA and improving the physiology of damaged skin. PMID:28640219

Development of a Full-Thickness Human Skin Equivalent In Vitro Model Derived from TERT-Immortalized Keratinocytes and Fibroblasts

PubMed Central

Reijnders, Christianne M.A.; van Lier, Amanda; Roffel, Sanne; Kramer, Duco; Scheper, Rik J.

2015-01-01

Currently, human skin equivalents (HSEs) used for in vitro assays (e.g., for wound healing) make use of primary human skin cells. Limitations of primary keratinocytes and fibroblasts include availability of donor skin and donor variation. The use of physiologically relevant cell lines could solve these limitations. The aim was to develop a fully differentiated HSE constructed entirely from human skin cell lines, which could be applied for in vitro wound-healing assays. Skin equivalents were constructed from human TERT-immortalized keratinocytes and fibroblasts (TERT-HSE) and compared with native skin and primary HSEs. HSEs were characterized by hematoxylin–eosin and immunohistochemical stainings with markers for epidermal proliferation and differentiation, basement membrane (BM), fibroblasts, and the extracellular matrix (ECM). Ultrastructure was determined with electron microscopy. To test the functionality of the TERT-HSE, burn and cold injuries were applied, followed by immunohistochemical stainings, measurement of reepithelialization, and determination of secreted wound-healing mediators. The TERT-HSE was composed of a fully differentiated epidermis and a fibroblast-populated dermis comparable to native skin and primary HSE. The epidermis consisted of proliferating keratinocytes within the basal layer, followed by multiple spinous layers, a granular layer, and cornified layers. Within the TERT-HSE, the membrane junctions such as corneosomes, desmosomes, and hemidesmosomes were well developed as shown by ultrastructure pictures. Furthermore, the BM consisted of a lamina lucida and lamina densa comparable to native skin. The dermal matrix of the TERT-HSE was more similar to native skin than the primary construct, since collagen III, an ECM marker, was present in TERT-HSEs and absent in primary HSEs. After wounding, the TERT-HSE was able to reepithelialize and secrete inflammatory wound-healing mediators. In conclusion, the novel TERT-HSE, constructed entirely from human cell lines, provides an excellent opportunity to study in vitro skin biology and can also be used for drug targeting and testing new therapeutics, and ultimately, for incorporating into skin-on-a chip in the future. PMID:26135533

Development of a Full-Thickness Human Skin Equivalent In Vitro Model Derived from TERT-Immortalized Keratinocytes and Fibroblasts.

PubMed

Reijnders, Christianne M A; van Lier, Amanda; Roffel, Sanne; Kramer, Duco; Scheper, Rik J; Gibbs, Susan

2015-09-01

Currently, human skin equivalents (HSEs) used for in vitro assays (e.g., for wound healing) make use of primary human skin cells. Limitations of primary keratinocytes and fibroblasts include availability of donor skin and donor variation. The use of physiologically relevant cell lines could solve these limitations. The aim was to develop a fully differentiated HSE constructed entirely from human skin cell lines, which could be applied for in vitro wound-healing assays. Skin equivalents were constructed from human TERT-immortalized keratinocytes and fibroblasts (TERT-HSE) and compared with native skin and primary HSEs. HSEs were characterized by hematoxylin-eosin and immunohistochemical stainings with markers for epidermal proliferation and differentiation, basement membrane (BM), fibroblasts, and the extracellular matrix (ECM). Ultrastructure was determined with electron microscopy. To test the functionality of the TERT-HSE, burn and cold injuries were applied, followed by immunohistochemical stainings, measurement of reepithelialization, and determination of secreted wound-healing mediators. The TERT-HSE was composed of a fully differentiated epidermis and a fibroblast-populated dermis comparable to native skin and primary HSE. The epidermis consisted of proliferating keratinocytes within the basal layer, followed by multiple spinous layers, a granular layer, and cornified layers. Within the TERT-HSE, the membrane junctions such as corneosomes, desmosomes, and hemidesmosomes were well developed as shown by ultrastructure pictures. Furthermore, the BM consisted of a lamina lucida and lamina densa comparable to native skin. The dermal matrix of the TERT-HSE was more similar to native skin than the primary construct, since collagen III, an ECM marker, was present in TERT-HSEs and absent in primary HSEs. After wounding, the TERT-HSE was able to reepithelialize and secrete inflammatory wound-healing mediators. In conclusion, the novel TERT-HSE, constructed entirely from human cell lines, provides an excellent opportunity to study in vitro skin biology and can also be used for drug targeting and testing new therapeutics, and ultimately, for incorporating into skin-on-a chip in the future.

Antitumor-promoting activity of oligomeric proanthocyanidins in mouse epidermis in vivo

Treesearch

Xiao Mei Gao; Elisabeth M. Perchellet; Hala U. Gali; Limarie Rodriguez; Richard W. Hemingway; Jean-Pierre Perchellet

1994-01-01

The flavanoid catechin and heterogenous samples of oligomeric proanthocyanidins extracted from various sources were compared for their ability to inhibit the biochemical and biological effects of l2-0-tetradecanoylphorbol-13-acetate (TPA) in mouse epidermis in vivo. Topical applications of catechin fail to alter the hydroperoxide response to TPA but...

Immunohistochemical expression of perforin in lichen planus lesions.

PubMed

Gaber, Mohamed Abdelwahed; Maraee, Alaa Hassan; Alsheraky, Dalia Rifaat; Azeem, Marwa Hussain Abdel

2014-12-01

Lichen planus (LP) is a chronic inflammatory papulosquamous skin disease characterized by epidermal basal cell damage and a particular band-like infiltrate predominantly of T cells in the upper dermis. It is characterized by the formation of colloid bodies representing apoptotic keratinocytes. The apoptotic process mediated by CD8+ cytotoxic T lymphocytes and natural killer cells mainly involves two distinct pathways: the perforin/granzyme pathway and the Fas/FasL pathway. So far, little is known regarding the role of perforin-mediated apoptosis in LP. Is to study the expression and distribution of perforin in the epidermis and dermis of lesional LP skin. Skin biopsy specimens from lesional skin of 31 patients with LP and 10 healthy persons were analyzed by immunohistochemistry. Significant accumulation of perforin + cells was found in both epidermis and dermis of LP lesions compared with healthy skin. Perforin expression was significantly upregulated in the epidermis of LP lesions. Accumulation of perforin + cells in the epidermis of LP lesions suggest a potential role of perforin in the apoptosis of basal keratinocytes.

Biochemical changes in desmosomes of bovine muzzle epidermis during differentiation.

PubMed

Konohana, A; Konohana, I; Roberts, G P; Marks, R

1987-10-01

Biochemical changes taking place in desmosomes during differentiation have been studied. Bovine muzzle epidermis was sliced horizontally into 6 layers, 0.2 mm thick, and desmosomes were isolated from each layer. These were then analyzed by polyacrylamide gel electrophoresis. The electrophoretic patterns of desmosomal proteins from the 6 layers were found to be qualitatively similar to each other, but there was an increase in the ratio of the amount of 150 kD glycoprotein (desmoglein I) relative to 240 and 210 kD proteins (desmoplakins) in the upper layers of the epidermis. This finding was supported by the similar increase observed in electrophoretic patterns of proteins extracted directly from each layer of the epidermis in electrophoretic sample buffer. In order to study the fate of desmosomal components in the stratum corneum, serial skin surface biopsies were stained with antisera against desmosomal components using indirect immunofluorescence techniques. This experiment showed that desmosomal proteins and glycoproteins persist in the stratum corneum but quantitatively decrease in the outer layers. This decrease may play a significant role in desquamation.

Transdermal Delivery of Functional Collagen Via Polyvinylpyrrolidone Microneedles

PubMed Central

Sun, Wenchao; Inayathullah, Mohammed; Manoukian, Martin A. C.; Malkovskiy, Andrey V.; Manickam, Sathish; Marinkovich, M. Peter; Lane, Alfred T.; Tayebi, Lobat; Seifalian, Alexander M.; Rajadas, Jayakumar

2017-01-01

Collagen makes up a large proportion of the human body, particularly the skin. As the body ages, collagen content decreases, resulting in wrinkled skin and decreased wound healing capabilities. This paper presents a method of delivering type I collagen into porcine and human skin utilizing a polyvinylpyrrolidone microneedle delivery system. The microneedle patches were made with concentrations of 1, 2, 4, and 8% type I collagen (w/w). Microneedle structures and the distribution of collagen were characterized using scanning electron microscopy and confocal microscopy. Patches were then applied on the porcine and human skin, and their effectiveness was examined using fluorescence microscopy. The results illustrate that this microneedle delivery system is effective in delivering collagen I into the epidermis and dermis of porcine and human skin. Since the technique presented in this paper is quick, safe, effective and easy, it can be considered as a new collagen delivery method for cosmetic and therapeutic applications. PMID:26066056

Pigment Production Analysis in Human Melanoma Cells.

PubMed

Hopkin, Amelia Soto; Paterson, Elyse K; Ruiz, Rolando; Ganesan, Anand K

2016-05-25

The human epidermal melanocyte is a highly specialized pigmented cell that serves to protect the epidermis from ultraviolet (UV) damage through the production of melanin, or melanogenesis. Misregulation in melanogenesis leading to either hyper- or hypo-pigmentation is found in human diseases such as malasma and vitiligo. Current therapies for these diseases are largely unsuccessful and the need for new therapies is necessary. In order to identify genes and or compounds that can alter melanogenesis, methods are required that can detect changes in pigment production as well as expression of key melanogenesis transcription factors and enzymes. Here we describe methods to detect changes in melanogenesis in a human melanoma cell line, MNT-1, by (1) analyzing pigment production by measuring the absorbance of melanin present by spectrophotometry, (2) analyzing transcript expression of potent regulators of melanogenesis by qunatitative reverse-transcription (RT)PCR and (3) analyzing protein expression of potent regulators of melanogenesis by Western blot (WB).

Generation of folliculogenic human epithelial stem cells from induced pluripotent stem cells

NASA Astrophysics Data System (ADS)

Yang, Ruifeng; Zheng, Ying; Burrows, Michelle; Liu, Shujing; Wei, Zhi; Nace, Arben; Guo, Wei; Kumar, Suresh; Cotsarelis, George; Xu, Xiaowei

2014-01-01

Epithelial stem cells (EpSCs) in the hair follicle bulge are required for hair follicle growth and cycling. The isolation and propagation of human EpSCs for tissue engineering purposes remains a challenge. Here we develop a strategy to differentiate human iPSCs (hiPSCs) into CD200+/ITGA6+ EpSCs that can reconstitute the epithelial components of the hair follicle and interfollicular epidermis. The hiPSC-derived CD200+/ITGA6+ cells show a similar gene expression signature as EpSCs directly isolated from human hair follicles. Human iPSC-derived CD200+/ITGA6+ cells are capable of generating all hair follicle lineages including the hair shaft, and the inner and outer root sheaths in skin reconstitution assays. The regenerated hair follicles possess a KRT15+ stem cell population and produce hair shafts expressing hair-specific keratins. These results suggest an approach for generating large numbers of human EpSCs for tissue engineering and new treatments for hair loss, wound healing and other degenerative skin disorders.

Generation of Genetically Modified Organotypic Skin Cultures Using Devitalized Human Dermis.

PubMed

Li, Jingting; Sen, George L

2015-12-14

Organotypic cultures allow the reconstitution of a 3D environment critical for cell-cell contact and cell-matrix interactions which mimics the function and physiology of their in vivo tissue counterparts. This is exemplified by organotypic skin cultures which faithfully recapitulates the epidermal differentiation and stratification program. Primary human epidermal keratinocytes are genetically manipulable through retroviruses where genes can be easily overexpressed or knocked down. These genetically modified keratinocytes can then be used to regenerate human epidermis in organotypic skin cultures providing a powerful model to study genetic pathways impacting epidermal growth, differentiation, and disease progression. The protocols presented here describe methods to prepare devitalized human dermis as well as to genetically manipulate primary human keratinocytes in order to generate organotypic skin cultures. Regenerated human skin can be used in downstream applications such as gene expression profiling, immunostaining, and chromatin immunoprecipitations followed by high throughput sequencing. Thus, generation of these genetically modified organotypic skin cultures will allow the determination of genes that are critical for maintaining skin homeostasis.

Plantar skin in type II diabetes: an investigation of protein glycation and biomechanical properties of plantar epidermis.

PubMed

Hashmi, Farina; Malone-Lee, James; Hounsell, Elizabeth

2006-01-01

The generation of thickened plantar stratum corneum (SC) in response to elevated pressures, places individuals with diabetes at risk of ulceration. Such a response may culminate from altered biochemical and physical states of the epidermis as a result of non-enzymatic glycation (NEG). The objective of this study was to quantify specific glycation products generated in plantar epidermal proteins in individuals with Type 2 Diabetes Mellitus (T2DM) and age-matched controls (n = 103 and n = 87, respectively) and to compare these data with the viscoelastic properties (in vivo) of the epidermis. Plantar SC and venous blood samples were collected from all participants for the quantification of furosine and pentosidine using high performance liquid chromatography (HPLC). The viscoelastic properties of plantar epidermis were measured by the application of negative pressure on the surface of the skin. Plantar epidermal thickness was measured using high frequency (20 MHz) ultrasonography. There was a significantly greater concentration of pentosidine in the SC samples from people with T2DM (p = 0.001). There was no correlation between the concentration of glycated proteins in the epidermal proteins and serum proteins (furosine r = - 0.115, pentosidine r = - 0.023). The plasticity of the epidermis was significantly lower in the T2DM group than the control group (p = 0.007). The results suggest that alterations in the glycation of plantar epidermal proteins may constitute additional aggravators of ulceration in people with T2DM.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okano, Junko, E-mail: jokano@belle.shiga-med.ac.jp; Kojima, Hideto; Katagi, Miwako

Bone marrow-derived cells (BMDCs) can migrate into the various organs in the mice irradiated by ionizing radiation (IR). However, it may not be the case in the skin. While IR is used for bone marrow (BM) transplantation, studying with the epidermal sheets demonstrated that the BMDC recruitment is extraordinarily rare in epidermis in the mouse. Herein, using the chimera mice with BM from green fluorescent protein (GFP) transgenic mice, we simply examined if BMDCs migrate into any layers in the total skin, as opposed to the epidermal sheets, in response to IR. Interestingly, we identified the presence of GFP-positive (GFP{supmore » +}) cells in the epidermis-dermis junction in the total skin sections although the epidermal cell sheets failed to have any GFP cells. To examine a possibility that the cells in the junction could be mechanically dissociated during separating epidermal sheets, we then salvaged such dissociated cells and examined its characteristics. Surprisingly, some GFP{sup +} cells were found in the salvaged cells, indicating that these cells could be derived from BM. In addition, such BMDCs were also associated with inflammation in the junction. In conclusion, BMDCs can migrate to and reside in the epidermis-dermis junction after IR. - Highlights: • Bone marrow-derived cells (BMDCs) migrate in the epidermis due to ionizing radiation (IR). • BMDCs dissociate from the epidermis-dermis junction in preparing epidermal sheets. • The doses of IR determine the location and the number of migrating BMDCs in the skin.« less

A novel method of measuring leaf epidermis and mesophyll stiffness shows the ubiquitous nature of the sandwich structure of leaf laminas in broad-leaved angiosperm species.

PubMed

Onoda, Yusuke; Schieving, Feike; Anten, Niels P R

2015-05-01

Plant leaves commonly exhibit a thin, flat structure that facilitates a high light interception per unit mass, but may increase risks of mechanical failure when subjected to gravity, wind and herbivory as well as other stresses. Leaf laminas are composed of thin epidermis layers and thicker intervening mesophyll layers, which resemble a composite material, i.e. sandwich structure, used in engineering constructions (e.g. airplane wings) where high bending stiffness with minimum weight is important. Yet, to what extent leaf laminas are mechanically designed and behave as a sandwich structure remains unclear. To resolve this issue, we developed and applied a novel method to estimate stiffness of epidermis- and mesophyll layers without separating the layers. Across a phylogenetically diverse range of 36 angiosperm species, the estimated Young's moduli (a measure of stiffness) of mesophyll layers were much lower than those of the epidermis layers, indicating that leaf laminas behaved similarly to efficient sandwich structures. The stiffness of epidermis layers was higher in evergreen species than in deciduous species, and strongly associated with cuticle thickness. The ubiquitous nature of sandwich structures in leaves across studied species suggests that the sandwich structure has evolutionary advantages as it enables leaves to be simultaneously thin and flat, efficiently capturing light and maintaining mechanical stability under various stresses. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

The arrector pili muscle, the bridge between the follicular stem cell niche and the interfollicular epidermis.

PubMed

Torkamani, Niloufar; Rufaut, Nicholas; Jones, Leslie; Sinclair, Rodney

2017-01-01

Proximally, the arrector pili muscle (APM) attaches to the follicular stem cell niche in the bulge, but its distal properties are comparatively unclear. In this work, a novel method employing an F-actin probe, phalloidin, was employed to visualize the APM anatomy. Phalloidin staining of the APM was validated by comparison with conventional antibodies/stains and by generating three-dimensional reconstructions. The proximal attachment of the APM to the bulge in 8 patients with androgenic alopecia was studied using Masson's trichrome stain. Phalloidin visualized extensive branching of the APM. The distal end of the human APM exhibits a unique "C"-shaped structure connecting to the dermal-epidermal junction. The proximal APM attachment was observed to be lost or extremely miniaturized in androgenic alopecia. The unique shape, location, and attachment sites of the APM suggest a significant role for this muscle in maintaining follicular integrity. Proximally, the APM encircles the follicular unit and only attaches to the primary hair follicle in the bulge; this attachment is lost in irreversible hair loss. The APM exhibits an arborized morphology as it ascends toward the epidermis, and anchors to the basement membrane.

Human COL7A1-corrected induced pluripotent stem cells for the treatment of recessive dystrophic epidermolysis bullosa

PubMed Central

Sebastiano, Vittorio; Zhen, Hanson Hui; Haddad, Bahareh; Bashkirova, Elizaveta; Melo, Sandra P.; Wang, Pei; Leung, Thomas L.; Siprashvili, Zurab; Tichy, Andrea; Li, Jiang; Ameen, Mohammed; Hawkins, John; Lee, Susie; Li, Lingjie; Schwertschkow, Aaron; Bauer, Gerhard; Lisowski, Leszek; Kay, Mark A.; Kim, Seung K.; Lane, Alfred T.; Wernig, Marius; Oro, Anthony E.

2015-01-01

Patients with recessive dystrophic epidermolysis bullosa (RDEB) lack functional type VII collagen owing to mutations in the gene COL7A1 and suffer severe blistering and chronic wounds that ultimately lead to infection and development of lethal squamous cell carcinoma. The discovery of induced pluripotent stem cells (iPSCs) and the ability to edit the genome bring the possibility to provide definitive genetic therapy through corrected autologous tissues. We generated patient-derived COL7A1-corrected epithelial keratinocyte sheets for autologous grafting. We demonstrate the utility of sequential reprogramming and adenovirus-associated viral genome editing to generate corrected iPSC banks. iPSC-derived keratinocytes were produced with minimal heterogeneity, and these cells secreted wild-type type VII collagen, resulting in stratified epidermis in vitro in organotypic cultures and in vivo in mice. Sequencing of corrected cell lines before tissue formation revealed heterogeneity of cancer-predisposing mutations, allowing us to select COL7A1-corrected banks with minimal mutational burden for downstream epidermis production. Our results provide a clinical platform to use iPSCs in the treatment of debilitating genodermatoses, such as RDEB. PMID:25429056

Retrieval of optical properties of skin from measurement and modeling the diffuse reflectance

NASA Astrophysics Data System (ADS)

Douven, Lucien F. A.; Lucassen, Gerald W.

2000-06-01

We present results on the retrieval of skin optical properties obtained by fitting of measurements of the diffuse reflectance of human skin. Reflectance spectra are simulated using an analytical model based on the diffusion approximation. This model is implemented in a simplex fit routine. The skin optical model used consists of five layers representing epidermis, capillary blood plexus, dermis, deep blood plexus and hypodermis. The optical properties of each layer are assumed homogeneously distributed. The main optical absorbers included are melanin in epidermis and blood. The experimental setup consists of a HP photospectrometer equipped with a remote fiber head. Total reflectance spectra were measured in the 400 - 820 nm wavelength range on the volar underarm of 19 volunteers under various conditions influencing the blood content and oxygenation degree. Changes in the reflectance spectra were observed. Using the fit routine changes in blood content in the capillary blood plexus and in the deep blood plexus could be quantified. These showed different influences on the total reflectance. The method can be helpful to quantitatively assess changes in skin color appearance such as occurs in the treatment of port wine stains, blanching, skin irritation and tanning.

Oxidative Stress in Aging Human Skin

PubMed Central

Rinnerthaler, Mark; Bischof, Johannes; Streubel, Maria Karolin; Trost, Andrea; Richter, Klaus

2015-01-01

Oxidative stress in skin plays a major role in the aging process. This is true for intrinsic aging and even more for extrinsic aging. Although the results are quite different in dermis and epidermis, extrinsic aging is driven to a large extent by oxidative stress caused by UV irradiation. In this review the overall effects of oxidative stress are discussed as well as the sources of ROS including the mitochondrial ETC, peroxisomal and ER localized proteins, the Fenton reaction, and such enzymes as cyclooxygenases, lipoxygenases, xanthine oxidases, and NADPH oxidases. Furthermore, the defense mechanisms against oxidative stress ranging from enzymes like superoxide dismutases, catalases, peroxiredoxins, and GSH peroxidases to organic compounds such as L-ascorbate, α-tocopherol, beta-carotene, uric acid, CoQ10, and glutathione are described in more detail. In addition the oxidative stress induced modifications caused to proteins, lipids and DNA are discussed. Finally age-related changes of the skin are also a topic of this review. They include a disruption of the epidermal calcium gradient in old skin with an accompanying change in the composition of the cornified envelope. This modified cornified envelope also leads to an altered anti-oxidative capacity and a reduced barrier function of the epidermis. PMID:25906193

Hydrodynamic gene delivery in human skin using a hollow microneedle device.

PubMed

Dul, M; Stefanidou, M; Porta, P; Serve, J; O'Mahony, C; Malissen, B; Henri, S; Levin, Y; Kochba, E; Wong, F S; Dayan, C; Coulman, S A; Birchall, J C

2017-11-10

Microneedle devices have been proposed as a minimally invasive delivery system for the intradermal administration of nucleic acids, both plasmid DNA (pDNA) and siRNA, to treat localised disease or provide vaccination. Different microneedle types and application methods have been investigated in the laboratory, but limited and irreproducible levels of gene expression have proven to be significant challenges to pre-clinical to clinical progression. This study is the first to explore the potential of a hollow microneedle device for the delivery and subsequent expression of pDNA in human skin. The regulatory approved MicronJet600® (MicronJet hereafter) device was used to deliver reporter plasmids (pCMVβ and pEGFP-N1) into viable excised human skin. Exogenous gene expression was subsequently detected at multiple locations that were distant from the injection site but within the confines of the bleb created by the intradermal bolus. The observed levels of gene expression in the tissue are at least comparable to that achieved by the most invasive microneedle application methods e.g. lateral application of a microneedle. Gene expression was predominantly located in the epidermis, although also evident in the papillary dermis. Optical coherence tomography permitted real time visualisation of the sub-surface skin architecture and, unlike a conventional intradermal injection, MicronJet administration of a 50μL bolus appears to create multiple superficial microdisruptions in the papillary dermis and epidermis. These were co-localised with expression of the pCMVβ reporter plasmid. We have therefore shown, for the first time, that a hollow microneedle device can facilitate efficient and reproducible gene expression of exogenous naked pDNA in human skin using volumes that are considered to be standard for intradermal administration, and postulate a hydrodynamic effect as the mechanism of gene delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of the effect of fatty alcohols on the permeation of melatonin between porcine and human skin.

PubMed

Andega, S; Kanikkannan, N; Singh, M

2001-11-09

Melatonin (MT) is a hormone secreted by the pineal gland that plays an important role in the regulation of the circadian sleep-wake cycle. It would be advantageous to administer MT using a transdermal delivery system for the treatment of sleep disorders such as delayed sleep syndrome, jet lag in travelers, cosmonauts and shift workers. The porcine skin has been found to have similar morphological and functional characteristics as human skin. The elastic fibres in the dermis, enzyme pattern of the epidermis, epidermal tissue turnover time, keratinous proteins and thickness of epidermis of porcine skin are similar to human skin. However, the fat deposition and vascularisation of the cutaneous glands of porcine skin are different from human skin. In addition, porcine skin has been found to have a close permeability character to human skin. However, the comparative effect of chemical penetration enhancers on the permeation of drugs between porcine and human skin has not been reported. The purpose of this study was to compare the effect of fatty alcohols on the permeability of porcine and human skin using MT as a model compound. The effect of saturated fatty alcohols (octanol, nonanol, decanol, undecanol, lauryl alcohol, tridecanol, myristyl alcohol) and unsaturated fatty alcohols (oleyl alcohol, linoleyl alcohol, linolenyl alcohol) at 5% concentration was tested across dermatomed porcine and human skin. Our studies showed a parabolic relationship between the carbon chain length of saturated fatty alcohols and permeation enhancement of MT with both porcine and human skin. Maximum permeation of MT was observed when fatty alcohol carbon chain length was 10. In general, as the level of unsaturation increased from one to two double bonds, there was an increase in the permeation of MT both in porcine and human skin. However, a decrease in the permeation was observed with three double bonds. Regression analysis using the steady state flux data showed a significant positive correlation between porcine and human skin for saturated fatty alcohols (r(2)=0.8868, P=0.0005). However, though a positive correlation was observed between the porcine and human skin (r(2)=0.8638), the correlation was statistically insignificant (P=0.0706). The static diffusion cell system employed in this study has major artifact compared to a flow through system. In conclusion, the permeability of porcine skin to MT in the presence of saturated and unsaturated fatty alcohols was qualitatively similar to human skin but quantitatively different with some fatty alcohols.

BETA-GAMMA PERSONNEL DOSIMETER

DOEpatents

Davis, D.M.; Gupton, E.D.; Hart, J.C.; Hull, A.P.

1961-01-17

A personnel dosimeter is offered which is sensitive to both gamma and soft beta radiations from all directions within a hemisphere. The device is in the shape of a small pill box which is worn on a worker-s wrist. The top and sides of the device are provided with 50 per cent void areas to give 50 per cent response to the beta rays and complete response to the gamma rays. The device is so constructed as to have a response which will approximate the dose received by the basal layer of the human epidermis.

[Advances in the research of function of Merkel cells in tactile formation of skin].

PubMed

You, X; Wei, Z R

2018-01-20

Skin is the largest sense organ of human, with many mechanoreceptor cells under epidermis or dermis of skin and Merkel cell is one of them. It has been confirmed that Merkel cells play an important role in the process of mechanical transmission of mammalian soft tactile stimulation. Researches showed that Merkel cells had close relation to tactile formation and functioned by Merkel cell-neurite complexes and ion channels Piezo2. This article reviews Merkel cells and the function, problem and prospect of Merkel cells in tactile formation.

Antitumor-promoting activity of oligomeric proanthocyanidins in mouse epidermis in vivo

Treesearch

Mei Xiao Gao; Elisabeth M. Perchellet; Hala U. Gali; Limarie Rodriguez; Richard W. Hemingway; Jean-Pierre Perchellet

1994-01-01

The flavanoid catechin and heterogenous samples of oligomeric proanthocyanidins extracted from various sources were compared for their ability to inhibit the biochemical and biological effects of 12-o-tertra-decanoylphorbol-13-acetate (TPA) in mouse epidermis in vivo. Topical applications of catechin fail to alter the hydroperoxide response to TPA but inhibit the...

Adult amphibian epidermal proteins: biochemical characterization and developmental appearance.

PubMed

Reeves, O R

1975-08-01

The keratin-like proteins (KLPs) from the epidermis of adult frogs of the species Xenopus laevis have been isolated and biochemically characterized by means of polyacrylamide gel electrophoresis, amino acid analysis, tryptic peptide mapping, amino-terminal end-group analysis and isoelectric focusing. One particular protein fraction of rather unusual amino acid composition found only in epidermal tissue was isolated in quantity by preparative gel electrophoresis and monospecific antibodies prepared against it. Using this anti-KLP antibody preparation it was possible to show that at least one kine of keratin-like protein characteristic of the adult epidermis first appears within the larval epidermis during metamorphosis. This is the first reported biochemical characterization of a tissue-specific protien from adult amphibian skin.

Channel catfish response to ultraviolet-B radiation

USGS Publications Warehouse

Ewing, M.S.; Blazer, V.S.; Fabacher, D.L.; Little, E.E.; Kocan, K.M.

1999-01-01

Fingerling channel catfish Ictalurus punctatus exposed to simulated ultraviolet-B radiation at an average daily dose of 2.9 J/cm2 were quite sensitive to the radiation. After a 24-h exposure, thinning of the most dorsal epidermis frequently was accompanied by edema. Compared with epidermis of unexposed fish, mucous cells in exposed fish were less superficial and club cells were less numerous both dorsally and high on the lateral surface of the body. Sunburn cells with pyknotic nuclei were evident in the epidermis of exposed fish. Among fish exposed for 48 h, focal necrosis and sloughing of the outer epidermal layer were widespread. A methanol-extractable skin substance that is associated with resistance to sunburn in other fish species was not detected in channel catfish.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Huan; Zhang, Weiguo; Qian, Yu

This study investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn inPhragmites australisroot system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X-ray microfluorescence, synchrotron transmission X-ray microscope measurement and synchrotron X-ray absorption near-edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils.Phragmites australissamples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that Fe nanoparticles are present in the root epidermis and thatmore » other metals correlate significantly with Fe, suggesting that Fe nanoparticles play an important role in metal scavenging in the epidermis.« less

Number of Langerhans cells is decreased in premalignant keratosis and skin cancers.

PubMed

Shevchuk, Z; Filip, A; Shevchuk, V; Kashuba, E

2014-03-01

It was shown earlier that a number of CD207 positive Langerhans cells was lower in basal cell carcinomas than in the normal epidermis. Moreover, benign skin lesions presented a higher number of Langerhans cells when they were compared to malignant tumors. To count Langerhans cells, assessing expression levels of CD1A and CD207 markers in actinic keratosis, basal and squamous cell carcinomas, compared with the normal skin. Comparison of Langerhans cells might give a valuable prognostic marker for skin cancer. Immunohistochemistry and methods of statistics were used. Expression of CD1A and CD207 markers was assessed in tumor samples of actinic keratosis, cutaneous basal and squamous cell carcinomas, in comparison with the normal skin. In each cohort there were 40 patients (and 11 healthy individuals). We have shown that the number of Langerhans cells is considerably lower in cutaneous basal and squamous cell carcinomas, compared with their number in the normal skin (p < 0.0001). CD1A expression correlated with CD207 expression only in the control group. There was no correlation in actinic keratosis, basal and squamous cell carcinoma. This may suggest an alteration of Langerhans cells phenotype in skin neoplastic diseases, making the number of Langerhans cells a valuable prognostic factor for skin tumors.

Epidermal Notch1 recruits RORγ(+) group 3 innate lymphoid cells to orchestrate normal skin repair.

PubMed

Li, Zhi; Hodgkinson, Tom; Gothard, Elizabeth J; Boroumand, Soulmaz; Lamb, Rebecca; Cummins, Ian; Narang, Priyanka; Sawtell, Amy; Coles, Jenny; Leonov, German; Reboldi, Andrea; Buckley, Christopher D; Cupedo, Tom; Siebel, Christian; Bayat, Ardeshir; Coles, Mark C; Ambler, Carrie A

2016-04-21

Notch has a well-defined role in controlling cell fate decisions in the embryo and the adult epidermis and immune systems, yet emerging evidence suggests Notch also directs non-cell-autonomous signalling in adult tissues. Here, we show that Notch1 works as a damage response signal. Epidermal Notch induces recruitment of immune cell subsets including RORγ(+) ILC3s into wounded dermis; RORγ(+) ILC3s are potent sources of IL17F in wounds and control immunological and epidermal cell responses. Mice deficient for RORγ(+) ILC3s heal wounds poorly resulting from delayed epidermal proliferation and macrophage recruitment in a CCL3-dependent process. Notch1 upregulates TNFα and the ILC3 recruitment chemokines CCL20 and CXCL13. TNFα, as a Notch1 effector, directs ILC3 localization and rates of wound healing. Altogether these findings suggest that Notch is a key stress/injury signal in skin epithelium driving innate immune cell recruitment and normal skin tissue repair.

Preneoplastic lesion growth driven by the death of adjacent normal stem cells

PubMed Central

Chao, Dennis L.; Eck, J. Thomas; Brash, Douglas E.; Maley, Carlo C.; Luebeck, E. Georg

2008-01-01

Clonal expansion of premalignant lesions is an important step in the progression to cancer. This process is commonly considered to be a consequence of sustaining a proliferative mutation. Here, we investigate whether the growth trajectory of clones can be better described by a model in which clone growth does not depend on a proliferative advantage. We developed a simple computer model of clonal expansion in an epithelium in which mutant clones can only colonize space left unoccupied by the death of adjacent normal stem cells. In this model, competition for space occurs along the frontier between mutant and normal territories, and both the shapes and the growth rates of lesions are governed by the differences between mutant and normal cells' replication or apoptosis rates. The behavior of this model of clonal expansion along a mutant clone's frontier, when apoptosis of both normal and mutant cells is included, matches the growth of UVB-induced p53-mutant clones in mouse dorsal epidermis better than a standard exponential growth model that does not include tissue architecture. The model predicts precancer cell mutation and death rates that agree with biological observations. These results support the hypothesis that clonal expansion of premalignant lesions can be driven by agents, such as ionizing or nonionizing radiation, that cause cell killing but do not directly stimulate cell replication. PMID:18815380

The importance of consumption of the epidermis in malignant melanoma and correlation with clinicopathological prognostic parameters.

PubMed

Seçkin, Selda; Ozgũn, Elmas

2011-01-01

The aim of the study was to investigate the importance of consumption of the epidermis as an additional diagnostic criteria for malignant melanoma and to evaluate its relationship to clinicopathological findings. The age, gender, localization of the lesion and the histopathological parameters such as tumor type, Breslow thickness, ulceration, Clark's level, mitosis/mm2, lymphocytic infiltration were noted in 40 malignant melanoma cases. Consumption of the epidermis was evaluated in tumor sections. Consumption of the epidermis (COE) due to thinning of the epidermis and loss of rete ridges was noted as (+) or (-). Furthermore, COE was compared with clinical and histopathological parameters. The Shapiro Wilk and Logistic Regression tests were used for statistical analysis. The results were accepted as significant if the p value was < 0.05. COE was detected in 60% (24/40) of malignant melanoma cases. A positive correlation was present between COE and head and neck localization (p = 0,698), superficial spreading melanoma (p = 0,341), ulceration (p = 0,097) and brisk lymphocytic infiltration (p = 0,200) but the results were not statistically significant. COE was frequently detected in males but the difference was not statistically significant (p = 0.796). There was no correlation or significant statistical association between COE and age, Breslow thickness, Clark's level or the mitotic index. The detection of COE in most of the patients suggests that COE could be a histopathological criterion in the diagnosis of malignant melanoma. The frequent association between COE and the presence of ulceration could also direct attention to COE as regards prognostic importance.

Nuclear Trapping Controls the Position-Dependent Localization of CAPRICE in the Root Epidermis of Arabidopsis1[C][W

PubMed Central

Kang, Yeon Hee; Song, Sang-Kee; Schiefelbein, John; Lee, Myeong Min

2013-01-01

Cell fate determination and differentiation are central processes in the development of multicellular organisms, and the Arabidopsis (Arabidopsis thaliana) root epidermis provides a model system to study the molecular basis of these processes. A lateral inhibition mechanism mediated by an R3 single-repeat MYB protein, CAPRICE (CPC), has been proposed to explain the specification of the two types of root epidermal cells (hair cells and nonhair cells). However, it is not clear how CPC acts preferentially in the H-position cells, rather than the N-position cells, where its gene is expressed. To explore this issue, we examined the effect of misexpressed CPC on cell fate specification and CPC localization in the root epidermis. We show that CPC is able to move readily within the root epidermis when its expression level is high and that CPC can induce the hair cell fate in a cell-autonomous manner. We provide evidence that CPC is capable of moving from the stele tissue in the center of the root to the outermost epidermal layer, where it can induce the hair cell fate. In addition, we show that CPC protein accumulates primarily in the nuclei of H-position cells in the early meristematic region, and this localization requires the H-cell-expressed ENHANCER OF GLABRA3 (EGL3) basic helix-loop-helix transcription factor. These results suggest that cell-cell movement of CPC occurs readily within the meristematic region of the root and that EGL3 preferentially traps the CPC protein in the H-position cells of the epidermis. PMID:23832626

DEFECTIVE KERNEL1 (DEK1) Regulates Cell Walls in the Leaf Epidermis1

PubMed Central

Amanda, Dhika; Ingram, Gwyneth C.

2016-01-01

The plant epidermis is crucial to survival, regulating interactions with the environment and controlling plant growth. The phytocalpain DEFECTIVE KERNEL1 (DEK1) is a master regulator of epidermal differentiation and maintenance, acting upstream of epidermis-specific transcription factors, and is required for correct cell adhesion. It is currently unclear how changes in DEK1 lead to cellular defects in the epidermis and the pathways through which DEK1 acts. We have combined growth kinematic studies, cell wall analysis, and transcriptional analysis of genes downstream of DEK1 to determine the cause of phenotypic changes observed in DEK1-modulated lines of Arabidopsis (Arabidopsis thaliana). We reveal a novel role for DEK1 in the regulation of leaf epidermal cell wall structure. Lines with altered DEK1 activity have epidermis-specific changes in the thickness and polysaccharide composition of cell walls that likely underlie the loss of adhesion between epidermal cells in plants with reduced levels of DEK1 and changes in leaf shape and size in plants constitutively overexpressing the active CALPAIN domain of DEK1. Calpain-overexpressing plants also have increased levels of cellulose and pectins in epidermal cell walls, and this is correlated with the expression of several cell wall-related genes, linking transcriptional regulation downstream of DEK1 with cellular effects. These findings significantly advance our understanding of the role of the epidermal cell walls in growth regulation and establish a new role for DEK1 in pathways regulating epidermal cell wall deposition and remodeling. PMID:27756823

A mechanistic model of environmental oxygen influence on the deterministic effects to human skin from space radiations

NASA Astrophysics Data System (ADS)

Flores-McLaughlin, John

During human spaceflight missions, controlled variation of atmospheric pressure and oxygen concentration from a sea-level based normal to hyperoxic levels may occur as part of operational procedure. This activity is of interest because it provides the relevant radiation exposure and dynamic oxygen concentration parameters that may lead to varying radiation sensitivity in the skin and other organs. Tumor hypoxia has been indicated as a primary factor in the decrease in efficacy of radiation therapy. These oxygen concentration effects have been largely demonstrated with low-LET radiations and to a lesser degree with high-LET primary radiations such as protons and heavy ions common in space exposure. In order to analyze the variation of oxygen concentration in human skin from spaceflight activities, a mathematical model of oxygen transport through the human cardiorespiratory system with pulmonary and cutaneous intake was implemented. Oxygen concentration was simulated at the various skin layers, from dermis to epidermis. Skin surface radiation doses and spectra from relatively high flux Solar Particle Events (SPEs) were calculated by the PHITS radiation transport code over a range of spacecraft and spacesuit thicknesses in terms of aluminum equivalence. A series of anatomical skin and shielding thicknesses were chosen to encompass the scope of radiation exposure levels as indicated by existing NASA skin phantom studies. To model the influence of oxygen with radiation exposure, microdosimetric oxygen fixation simulations were implemented using the Monte-Carlo-Damage-Simulation (MCDS) code. From these outputs, occurrence of DNA double strand breaks (DSBs) and relative biological effect (RBE) from radiation exposure with oxygen concentration dependence was established and correlated to spaceflight activities. It was determined that minimal but observable oxygen concentration transients occur in skin during environmental oxygen changes in spaceflight. The most significant transients occurred in the thickest epidermal layers with relatively high amounts of diffusion. Accordingly, these thickest epidermal layers also showed the greatest spaceflight induced transients of RBE relative to sea-level based atmosphere exposures.

Morphometric analysis of epidermal differentiation in primary roots of Zea mays

NASA Technical Reports Server (NTRS)

Moore, R.; Smith, H. S.

1990-01-01

Epidermal differentiation in primary roots of Zea mays was divided into six cell types based on cellular shape and cytoplasmic appearance. These six cell types are: 1) apical protoderm, located at the tip of the root pole and characterized by periclinally flattened cells; 2) cuboidal protoderm, located approximately 230 microns from the root pole and characterized by cuboidal cells; 3) tabular epidermis, located approximately 450 microns from the root pole and characterized by anticlinally flattened cells; 4) cuboidal epidermis, located approximately 900 microns from the root pole and characterized by cuboidal cells having numerous small vacuoles; 5) vacuolate cuboidal epidermis, located approximately 1,500 microns from the root pole and characterized by cuboidal cells containing several large vacuoles; and 6) columnar epidermis, located approximately 2,200 microns from the root pole (i.e., at the beginning of the zone of elongation) and characterized by elongated cells. We also used stereology to quantify the cellular changes associated with epidermal differentiation. The quiescent center and the apical protoderm have significantly different ultrastructures. The relative volume of dictyosomes increases dramatically during the early stages of epidermal differentiation. This increase correlates inversely with the amount of coverage provided by the root cap and mucilage.

Root growth regulation and gravitropism in maize roots does not require the epidermis

NASA Technical Reports Server (NTRS)

Bjorkman, T.; Cleland, R. E.

1991-01-01

We have earlier published observations showing that endogenous alterations in growth rate during gravitropism in maize roots (Zea mays L.) are unaffected by the orientation of cuts which remove epidermal and cortical tissue in the growing zone (Bjorkman and Cleland, 1988, Planta 176, 513-518). We concluded that the epidermis and cortex are not essential for transporting a growth-regulating signal in gravitropism or straight growth, nor for regulating the rate of tissue expansion. This conclusion has been challenged by Yang et al. (1990, Planta 180, 530-536), who contend that a shallow girdle around the entire perimeter of the root blocks gravitropic curvature and that this inhibition is the result of a requirement for epidermal cells to transport the growth-regulating signal. In this paper we demonstrate that the entire epidermis can be removed without blocking gravitropic curvature and show that the position of narrow girdles does not affect the location of curvature. We therefore conclude that the epidermis is not required for transport of a growth-regulating substance from the root cap to the growing zone, nor does it regulate the growth rate of the elongating zone of roots.

Transdermal delivery of carvedilol containing glycyrrhizin and chitosan as permeation enhancers: biochemical, biophysical, microscopic and pharmacodynamic evaluation.

PubMed

Sapra, Bharti; Jain, Subheet; Tiwary, A K

2008-09-01

The present study was aimed at unveiling the influence of glycyrrhizin and chitosan on rat epidermis and to correlate these effects with percutaneous permeation characteristics of carvedilol. The permeation of carvedilol across excised rat epidermis was significantly higher (p < 0.05) when glycyrrhizin, chitosan, or glycyrrhizin-chitosan mixture was used as a donor vehicle as compared to propylene glycol:ethanol (7:3) mixture. Epidermis obtained after 12 hr treatment of viable rat skin with a glycyrrhizin-chitosan mixture showed significantly higher (p < 0.05) permeability to carvedilol as compared to that after treatment with glycyrrhizin or chitosan alone. Further, the application of patches containing glycyrrhizin-chitosan mixture resulted in sustained release of carvedilol, which was able to control the hypertension in deoxycorticosterone acetate induced hypertensive rats through 28 hr. Estimation of microconstituents in rat epidermis revealed maximum extraction of cholesterol, sphingosine, and triglycerides after treatment with glycyrrhizin-chitosan mixture. This was manifested in altered lipid and protein-specific thermotropic transitions. Further, increase in intercellular space, disordered lipid structure and corneocyte detachment as observed in SEM and TEM suggests great potential of glycyrrhizin for use as a percutaneous permeation enhancer.

Time course of pH change in plant epidermis using microscopic pH imaging system

NASA Astrophysics Data System (ADS)

Dan, Risako; Shimizu, Megumi; Kazama, Haruko; Sakaue, Hirotaka

2010-11-01

We established a microscopic pH imaging system to track the time course of pH change in plant epidermis in vivo. In the previous research, we have found out that anthocyanin containing cells have higher pH. However, it was not clear whether the anthocyanin increased the pH or anthocyanin was synthesized result from the higher pH. Therefore, we further investigated the relationship between anthocyanin and pH change. To track the time course of pH change in plant epidermis, we established a system using luminescent imaging technique. We used HPTS (8-Hydroxypyrene-1,3,6-Trisulfonate) as pH indicator and applied excitation ratio imaging method. Luminescent image was converted to a pH distribution by obtained in vitro calibration using known pH solution. Cellular level observation was enabled by merging microscopic color picture of the same region to the pH change image. The established system was applied to epidermal cells of red-tip leaf lettuce, Lactuca Sativa L. and the time course was tracked in the growth process. We would discuss about the relationship between anthocyanin and pH change in plant epidermis.

Onion epidermis as a new model to study the control of growth anisotropy in higher plants.

PubMed

Suslov, Dmitry; Verbelen, Jean-Pierre; Vissenberg, Kris

2009-01-01

To elucidate the role of cellulose microfibrils in the control of growth anisotropy, a link between their net orientation, in vitro cell wall extensibility, and anisotropic cell expansion was studied during development of the adaxial epidermis of onion (Allium cepa) bulb scales using polarization confocal microscopy, creep tests, and light microscopy. During growth the net cellulose alignment across the whole thickness of the outer epidermal wall changed from transverse through random to longitudinal and back to transverse relative to the bulb axis. Cell wall extension in vitro was always higher transverse than parallel to the net cellulose alignment. The direction of growth anisotropy was perpendicular to the net microfibril orientation and changed during development from longitudinal to transverse to the bulb axis. The correlation between the degree of growth anisotropy and the net cellulose alignment was poor. Thus the net cellulose microfibril orientation across the whole thickness of the outer periclinal epidermis wall defines the direction but not the degree of growth anisotropy. Strips isolated from the epidermis in the directions perpendicular and transverse to a net cellulose orientation can be used as an extensiometric model to prove a protein involvement in the control of growth anisotropy.

Ectopic expression of LEAFY COTYLEDON1-LIKE gene and localized auxin accumulation mark embryogenic competence in epiphyllous plants of Helianthus annuus × H. tuberosus

PubMed Central

Chiappetta, A.; Fambrini, M.; Petrarulo, M.; Rapparini, F.; Michelotti, V.; Bruno, L.; Greco, M.; Baraldi, R.; Salvini, M.; Pugliesi, C.; Bitonti, M. B.

2009-01-01

Background and Aims The clone EMB-2 of the interspecific hybrid Helianthus annuus × H. tuberosus provides an interesting system to study molecular and physiological aspects of somatic embryogenesis. Namely, in addition to non-epiphyllous (NEP) leaves that expand normally, EMB-2 produces epiphyllous (EP) leaves bearing embryos on the adaxial surface. This clone was used to investigate if the ectopic expression of H. annuus LEAFY COTYLEDON1-LIKE (Ha-L1L) gene and auxin activity are correlated with the establishment of embryogenic competence. Methods Ha-L1L expression was evaluated by semi-quantitative RT-PCR and in situ hybridization. The endogenous level and spatial distribution of free indole-3-acetic acid (IAA) were estimated by a capillary gas chromatography–mass spectrometry–selected ion monitoring method and an immuno-cytochemical approach. Key Results Ectopic expression of Ha-L1L was detected in specific cell domains of the adaxial epidermis of EP leaves prior to the development of ectopic embryos. Ha-L1L was expressed rapidly when NEP leaves were induced to regenerate somatic embryos by in vitro culture. Differences in auxin distribution pattern rather than in absolute level were observed between EP and A-2 leaves. More precisely, a strong IAA immuno-signal was detected in single cells or in small groups of cells along the epidermis of EP leaves and accompanied the early stages of embryo development. Changes in auxin level and distribution were observed in NEP leaves induced to regenerate by in vitro culture. Exogenous auxin treatments lightly influenced Ha-L1L transcript levels in spite of an enhancement of the regeneration frequency. Conclusions In EP leaves, Ha-L1L activity marks the putative founder cells of ectopic embryos. Although the ectopic expression of Ha-L1L seems to be not directly mediated by auxin levels per se, it was demonstrated that localized Ha-L1L expression and IAA accumulation in leaf epidermis domains represent early events of somatic embryogenesis displayed by the epiphyllous EMB-2 clone. PMID:19151043

RECENT DEVELOPMENTS IN SURGICAL SKIN PLANING

PubMed Central

Ayres, Samuel; Wilson, J. Walter; Luikart, Ralph

1958-01-01

In surgical skin planing steel wire brushes have been largely replaced by the less hazardous diamond chip burs or “fraises” and serrated steel wheels. In addition to acne pits and wrinkling, multiple actinic (senile) keratoses are an important indication for planing. Planing provides a nonscarring method for the treatment of existing keratoses, as well as a prophylaxis against skin cancer by replacing the sun-damaged, precancerous epidermis with new epidermal cells derived from the cutaneous adnexa (pilosebaceous and sweat gland units). There are clinical landmarks indicating the depth of planing which can serve as a guide to the operator and can be correlated with microscopic findings. The results of experiments on the comparative effects of refrigerants on animal and human skin indicate that human facial skin can tolerate considerable freezing with ethyl chloride or dichlorotetrafluoroethane (Freon 114) but that mixtures containing large proportions of the much colder dichlorodifluoromethane (Freon 12) may be undesirable. Refreezing an area of the skin in order to perform a more adequate planing is not considered hazardous. The regeneration of the skin following planing has three components: Epidermal, adnexal and dermal. The cells of the epidermis and the adnexa are equipotential. A knowledge of the anatomy of the acne pit enables the operator to decide which pits can be benefited by planing and which should be excised before planing. The successful treatment of acne pits of the face by planing in patients having keloids elsewhere on the body is reported. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7. PMID:13500217

The differentiation profile of the epithelium of the human lip.

PubMed

Barrett, A W; Morgan, M; Nwaeze, G; Kramer, G; Berkovitz, B K B

2005-04-01

The aim of this study was to analyse the immunohistochemical differentiation profile of the stratified squamous epithelium of the adult human lip. Full-thickness lower lips taken from 31 cadavers were analysed. Sections were stained with haematoxylin and eosin, periodic acid-Schiff (PAS), cytokeratins (CK), loricrin, involucrin, profilaggrin and filaggrin. The stratified squamous epithelium covering the lip could be divided into: (i) appendage-bearing, orthokeratinised epidermis; (ii) orthokeratinised vermilion which had a more prominent rete pattern than the epidermis; (iii) parakeratinised, PAS-positive intermediate zone; and (iv) non- or parakeratinised labial mucosal epithelium. Epithelial thickness increased gradually from the skin to the mucosal aspect. The CK pattern changed across the intermediate zone, with gradual loss of CK 1 and 10 from the skin, and CK 4, 13 and 19 from the mucosal, aspect. CK 5 and 14 were consistently expressed basally, and variably expressed suprabasally. Apart from labelling Merkel cells, CK 8, 18 and 20 were negative. Involucrin, which was present at all sites, was restricted to the stratum granulosum in skin, but extended into the stratum spinosum, and gradually into parabasal keratinocytes, across the vermilion and mucosa. Loricrin, profilaggrin and filaggrin were present in the stratum granulosum of orthokeratinised sites, but expression was abruptly lost at the junction between the vermilion and the intermediate zone. In conclusion, the phenotype of the stratified squamous epithelium covering the lip changes at, or across, the intermediate zone of the adult vermilion. It is possible that changes in the composition of the stratified squamous epithelium affect the colour of the vermilion.

Dermal penetration and metabolism of p-aminophenol and p-phenylenediamine: application of the EpiDerm human reconstructed epidermis model.

PubMed

Hu, Ting; Bailey, Ruth E; Morrall, Stephen W; Aardema, Marilyn J; Stanley, Lesley A; Skare, Julie A

2009-07-24

To address the provision of the 7th Amendment to the EU Cosmetics Directive banning the use of in vivo genotoxicity assays for testing cosmetic ingredients in 2009, the 3D EpiDerm reconstructed human skin micronucleus assay has been developed. To further characterise the EpiDerm tissue for potential use in genotoxicity testing, we have evaluated the dermal penetration and metabolism of two hair dye ingredients, p-aminophenol (PAP) and p-phenylenediamine (PPD) in this reconstructed epidermis model. When EpiDerm tissue was topically exposed to PAP or PPD for 30 min (typical for a hair dye exposure), the majority (80->90%) of PAP or PPD was excluded from skin tissue and removed by rinsing. After a 23.5h recovery period, the PAP fraction that did penetrate was completely N-acetylated to acetaminophen (APAP). Similarly, 30 min topical application of PPD resulted in the formation of the N-mono- and N,N'-diacetylated metabolites of PPD. These results are consistent with published data on the dermal metabolism of these compounds from other in vitro systems as well as from in vivo studies. When tissue was exposed topically (PAP) or via the culture media (PPD) for 24h, there was good batch-to-batch and donor-to-donor reproducibility in the penetration and metabolism of PAP and PPD. Overall, the results demonstrate that these two aromatic amines are biotransformed in 3D EpiDerm tissue via N-acetylation. Characterising the metabolic capability of EpiDerm tissue is important for the evaluation of this model for use in genotoxicity testing.

Protective effects of a cream containing Dead Sea minerals against UVB-induced stress in human skin.

PubMed

Portugal-Cohen, Meital; Soroka, Yoram; Ma'or, Zeevi; Oron, Miriam; Zioni, Tamar; Brégégère, François Menahem; Neuman, Rami; Kohen, Ron; Milner, Yoram

2009-09-01

Dead Sea (DS) mud and water are known for their unique composition of minerals, and for their therapeutic properties on psoriasis and other inflammatory skin diseases. Their mode of action, however, remains poorly known. To analyse the ability of Dermud, a leave-on skin preparation containing DS mud and other ingredients like DS water, zinc oxide, aloe-vera extract, pro-vitamin B5 and vitamin E, to antagonize biological effects induced by UVB irradiation in skin when topically applied in organ cultures. We have used human skin organ cultures as a model to assess the biological effects of UVB irradiation and of Dermud cream topical application. Skin pieces were analysed for mitochondrial activity by MTT assay, for apoptosis by caspase 3 assay, for cytokine secretion by solid phase ELISA, for overall antioxidant capacity by ferric reducing antioxidant power and Oxygen radical absorbance capacity assays (epidermis) or by cyclic voltammetry (external medium), and for uric acid (UA) content by HPLC. We report that UVB irradiation decreases cell viability, total antioxidant capacity and UA contents in the epidermis of skin organ cultures, while increasing the levels of apoptosis in cells and their cytokine secretion. Topical application of Dermud decreased all these effects significantly. Our results clearly show that Dermud has protective, anti-oxidant and anti-inflammatory properties that can antagonize biological effects of UVB irradiation in skin. It may therefore be able to reduce skin photodamage and photoaging, and more generally to reduce oxidative stress and inflammation in skin pathologies.

Study on the mechanism of human blood glucose concentration measuring using mid-infrared spectral analysis technology

NASA Astrophysics Data System (ADS)

Li, Xiang

2016-10-01

All forms of diabetes increase the risk of long-term complications. Blood glucose monitoring is of great importance for controlling diabetes procedure, preventing the complications and improving the patient's life quality. At present, the clinical blood glucose concentration measurement is invasive and could be replaced by noninvasive spectroscopy analytical techniques. The mid-infrared spectral region contains strong characteristic and well-defined absorption bands. Therefore, mid-infrared provides an opportunity for monitoring blood glucose invasively with only a few discrete bonds. Although the blood glucose concentration measurement using mid-infrared spectroscopy has a lot of advantages, the disadvantage is also obvious. The absorption in this infrared region is fundamental molecular group vibration. Absorption intensity is very strong, especially for biological molecules. In this paper, it figures out that the osmosis rate of glucose has a certain relationship with the blood glucose concentration. Therefore, blood glucose concentration could be measured indirectly by measuring the glucose exudate in epidermis layer. Human oral glucose tolerance tests were carried out to verify the correlation of glucose exudation in shallow layer of epidermis layer and blood glucose concentration. As it has been explained above, the mid-infrared spectral region contains well-defined absorption bands, the intensity of absorption peak around 1123 cm-1 was selected to measure the glucose and that around 1170 cm-1 was selected as reference. Ratio of absorption peak intensity was recorded for each set of measurement. The effect and importance of the cleaning the finger to be measured before spectrum measuring are discussed and also verified by experiment.

Comparison of interleukin 10 homologs on dermal wound healing using a novel human skin ex vivo organ culture model

PubMed Central

Balaji, Swathi; Moles, Chad M.; Bhattacharya, Sukanta S.; LeSaint, Maria; Dhamija, Yashu; Le, Louis D.; King, Alice; Kidd, Mykia; Bouso, Muhammad F.; Shaaban, Aimen; Crombleholme, Timothy M.; Bollyky, Paul; Keswani, Sundeep G.

2015-01-01

Background Anti-inflammatory cytokine interleukin (IL)-10 has been shown to induce regenerative healing in postnatal wounds. A viral homolog of IL-10 produced by human cytomegalovirus (CMV IL-10) similarly generates potent immunoregulatory effects, but its effects on wound healing have not been investigated. Currently, there are limited cost-effective methods of screening vulnerary therapeutics. Taken together, we aim to develop and validate a novel human ex vivo dermal wound model and hypothesize that CMV IL-10 will enhance dermal wound healing. Methods Full-thickness circular (6-mm) explants were taken from surgical skin samples and 3-mm full-thickness wounds were created. Explants were embedded in collagen I matrix and maintained in specially formulated media with the epidermis at air–liquid interface, and treated with human IL-10 or CMV IL-10 (200 ng/mL). The viability of cultured explants was validated by histology and lactate dehydrogenase (LDH) activity. Epithelial gap, epithelial height, basal keratinocyte migration, vascular endothelial growth factor levels, and neovascularization were measured at days 3 and 7 to determine IL-10 effects on wound healing. Results Culture explants at day 7 appeared similar to fresh skin in morphology, cell, and vessel density. By day 14, the epidermis separated from the dermis and the cell density diminished. Day 7 wounds appeared viable with advancing epithelial and basal keratinocyte migration with no evidence of necrosis. Cytotoxicity analysis via the quantification of LDH revealed no differences between controls and treated groups. There was a slight increase in the quantity of LDH in media at day 3; however, this decreased at day 5 and continued to decline up to day 21. CMV IL-10 treatment resulted in a significant decrease in the epithelial gap and an increase in epithelial height. There were no differences in the rates of basal keratinocyte migration at day 7 between treated and control groups. Interestingly, human IL-10 increased vascular endothelial growth factor expression and neovascularization compared with controls. Conclusions The human ex vivo wound model provides a simple and viable design to study dermal wound healing. Both IL-10 homologs demonstrate vulnerary effects. The viral homolog demonstrates enhanced effects on wound closure compared with human IL-10. These data represent a novel tool that can be used to screen therapeutics, such as CMV IL-10, before preclinical studies. PMID:24814764

Jet fuel toxicity: skin damage measured by 900-MHz MRI skin microscopy and visualization by 3D MR image processing.

PubMed

Sharma, Rakesh; Locke, Bruce R

2010-09-01

The toxicity of jet fuels was measured using noninvasive magnetic resonance microimaging (MRM) at 900-MHz magnetic field. The hypothesis was that MRM can visualize and measure the epidermis exfoliation and hair follicle size of rat skin tissue due to toxic skin irritation after skin exposure to jet fuels. High-resolution 900-MHz MRM was used to measure the change in size of hair follicle, epidermis thickening and dermis in the skin after jet fuel exposure. A number of imaging techniques utilized included magnetization transfer contrast (MTC), spin-lattice relaxation constant (T1-weighting), combination of T2-weighting with magnetic field inhomogeneity (T2*-weighting), magnetization transfer weighting, diffusion tensor weighting and chemical shift weighting. These techniques were used to obtain 2D slices and 3D multislice-multiecho images with high-contrast resolution and high magnetic resonance signal with better skin details. The segmented color-coded feature spaces after image processing of the epidermis and hair follicle structures were used to compare the toxic exposure to tetradecane, dodecane, hexadecane and JP-8 jet fuels. Jet fuel exposure caused skin damage (erythema) at high temperature in addition to chemical intoxication. Erythema scores of the skin were distinct for jet fuels. The multicontrast enhancement at optimized TE and TR parameters generated high MRM signal of different skin structures. The multiple contrast approach made visible details of skin structures by combining specific information achieved from each of the microimaging techniques. At short echo time, MRM images and digitized histological sections confirmed exfoliated epidermis, dermis thickening and hair follicle atrophy after exposure to jet fuels. MRM data showed correlation with the histopathology data for epidermis thickness (R(2)=0.9052, P<.0002) and hair root area (R(2)=0.88, P<.0002). The toxicity of jet fuels on skin structures was in the order of tetradecane>hexadecane>dodecane. The method showed a sensitivity of 87.5% and a specificity of 75%. By MR image processing, different color-coded skin structures were extracted and 3D shapes of the epidermis and hair follicle size were compared. In conclusion, high-resolution MRM measured the change in skin epidermis and hair follicle size due to toxicity of jet fuels. MRM offers a three-dimensional spatial visualization of the change in skin structures as a method of toxicity evaluation and for comparison of jet fuels.

Nuclear ribosome biogenesis mediated by the DIM1A rRNA dimethylase is required for organized root growth and epidermal patterning in Arabidopsis.

PubMed

Wieckowski, Yana; Schiefelbein, John

2012-07-01

Position-dependent patterning of hair and non-hair cells in the Arabidopsis thaliana root epidermis is a powerful system to study the molecular basis of cell fate specification. Here, we report an epidermal patterning mutant affecting the ADENOSINE DIMETHYL TRANSFERASE 1A (DIM1A) rRNA dimethylase gene, predicted to participate in rRNA posttranscriptional processing and base modification. Consistent with a role in ribosome biogenesis, DIM1A is preferentially expressed in regions of rapid growth, and its product is nuclear localized with nucleolus enrichment. Furthermore, DIM1A preferentially accumulates in the developing hair cells, and the dim1A point mutant alters the cell-specific expression of the transcriptional regulators GLABRA2, CAPRICE, and WEREWOLF. Together, these findings suggest that establishment of cell-specific gene expression during root epidermis development is dependent upon proper ribosome biogenesis, possibly due to the sensitivity of the cell fate decision to relatively small differences in gene regulatory activities. Consistent with its effect on the predicted S-adenosyl-l-Met binding site, dim1A plants lack the two 18S rRNA base modifications but exhibit normal pre-rRNA processing. In addition to root epidermal defects, the dim1A mutant exhibits abnormal root meristem division, leaf development, and trichome branching. Together, these findings provide new insights into the importance of rRNA base modifications and translation regulation for plant growth and development.

Nuclear Ribosome Biogenesis Mediated by the DIM1A rRNA Dimethylase Is Required for Organized Root Growth and Epidermal Patterning in Arabidopsis[C][W

PubMed Central

Wieckowski, Yana; Schiefelbein, John

2012-01-01

Position-dependent patterning of hair and non-hair cells in the Arabidopsis thaliana root epidermis is a powerful system to study the molecular basis of cell fate specification. Here, we report an epidermal patterning mutant affecting the ADENOSINE DIMETHYL TRANSFERASE 1A (DIM1A) rRNA dimethylase gene, predicted to participate in rRNA posttranscriptional processing and base modification. Consistent with a role in ribosome biogenesis, DIM1A is preferentially expressed in regions of rapid growth, and its product is nuclear localized with nucleolus enrichment. Furthermore, DIM1A preferentially accumulates in the developing hair cells, and the dim1A point mutant alters the cell-specific expression of the transcriptional regulators GLABRA2, CAPRICE, and WEREWOLF. Together, these findings suggest that establishment of cell-specific gene expression during root epidermis development is dependent upon proper ribosome biogenesis, possibly due to the sensitivity of the cell fate decision to relatively small differences in gene regulatory activities. Consistent with its effect on the predicted S-adenosyl-l-Met binding site, dim1A plants lack the two 18S rRNA base modifications but exhibit normal pre-rRNA processing. In addition to root epidermal defects, the dim1A mutant exhibits abnormal root meristem division, leaf development, and trichome branching. Together, these findings provide new insights into the importance of rRNA base modifications and translation regulation for plant growth and development. PMID:22829145

Filaggrin 2 deficiency results in abnormal cell-cell adhesion in the cornified cell layers and causes peeling skin syndrome type A.

PubMed

Mohamad, Janan; Sarig, Ofer; Godsel, Lisa M; Peled, Alon; Malchin, Natalia; Bochner, Ron; Vodo, Dan; Rabinowitz, Tom; Pavlovsky, Mor; Taiber, Shahar; Fried, Maya; Eskin-Schwartz, Marina; Assi, Siwar; Shomron, Noam; Uitto, Jouni; Koetsier, Jennifer L; Bergman, Reuven; Green, Kathleen J; Sprecher, Eli

2018-05-11

Peeling skin syndromes form a large and heterogeneous group of inherited disorders characterized by superficial detachment of the epidermal cornified cell layers, often associated with inflammatory features. Here we report on a consanguineous family featuring non-inflammatory peeling of the skin exacerbated by exposure to heat and mechanical stress. Whole exome sequencing revealed a homozygous nonsense mutation in FLG2, encoding filaggrin 2, which co-segregated with the disease phenotype in the family. The mutation was found to result in decreased FLG2 RNA levels as well almost total absence of filaggrin 2 in the patient epidermis. Filaggrin 2 was found to be expressed throughout the cornified cell layers and to co-localize with corneodesmosin which plays a crucial role in maintaining cell-cell adhesion in this region of the epidermis. Absence of filaggrin 2 in the patient skin was associated with markedly decreased corneodesmosin expression, which may contribute to the peeling phenotype displayed by the patients. Accordingly, using the dispase dissociation assay, we showed that FLG2 down-regulation interferes with keratinocyte cell-cell adhesion. Of particular interest, this effect was aggravated by temperature elevation, consistent with the clinical phenotype. Restoration of CDSN levels by ectopic expression rescued cell-cell adhesion.Taken together, the present data suggest that filaggrin 2 is essential for normal cell-cell adhesion in the cornified cell layers. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

The Dehydratase ADT3 Affects ROS Homeostasis and Cotyledon Development1[OPEN

PubMed Central

Para, Alessia; Muhammad, DurreShahwar; Naldrett, Michael J.; Warpeha, Katherine M.

2016-01-01

During the transition from seed to seedling, emerging embryos strategically balance available resources between building up defenses against environmental threats and initiating the developmental program that promotes the switch to autotrophy. We present evidence of a critical role for the phenylalanine (Phe) biosynthetic activity of AROGENATE DEHYDRATASE3 (ADT3) in coordinating reactive oxygen species (ROS) homeostasis and cotyledon development in etiolated Arabidopsis (Arabidopsis thaliana) seedlings. We show that ADT3 is expressed in the cotyledon and shoot apical meristem, mainly in the cytosol, and that the epidermis of adt3 cotyledons contains higher levels of ROS. Genome-wide proteomics of the adt3 mutant revealed a general down-regulation of plastidic proteins and ROS-scavenging enzymes, corroborating the hypothesis that the ADT3 supply of Phe is required to control ROS concentration and distribution to protect cellular components. In addition, loss of ADT3 disrupts cotyledon epidermal patterning by affecting the number and expansion of pavement cells and stomata cell fate specification; we also observed severe alterations in mesophyll cells, which lack oil bodies and normal plastids. Interestingly, up-regulation of the pathway leading to cuticle production is accompanied by an abnormal cuticle structure and/or deposition in the adt3 mutant. Such impairment results in an increase in cell permeability and provides a link to understand the cell defects in the adt3 cotyledon epidermis. We suggest an additional role of Phe in supplying nutrients to the young seedling. PMID:27540109

Mitotic activity in dorsal epidermis of Rana pipiens.

NASA Technical Reports Server (NTRS)

Garcia-Arce, H.; Mizell, S.

1972-01-01

Study of statistically significant rhythms of mitotic division in dorsal epidermis of frogs, Rana pipiens, exposed to a 12:12 light:dark environment for 14 days. The results include the findings that (1) male animals have a primary period of 22 hr in summer and 18 hr in winter, (2) female animals have an 18 hr period, and (3) parapinealectomy and blinding abolish the rhythm.

Molecular mechanisms of UVB-induced senescence of dermal fibroblasts and its relevance for photoaging of the human skin.

PubMed

Cavinato, Maria; Jansen-Dürr, Pidder

2017-08-01

Due to its ability to cross the epidermis and reach the upper dermis where it causes cumulative DNA damage and increased oxidative stress, UVB is considered the most harmful component of sunlight to the skin. The consequences of chronic exposition to UVB are related to photoaging and photocarcinogenesis. There are limitations to the study of human skin aging and for this reason the use of models is required. Human dermal fibroblasts submitted to mild and repeated doses of UVB are considered a versatile model to study UVB effects in the process of skin photoaging, which depends on the accumulation of senescent cells, in particular in the dermis. Here we provide updated information about the current model of UVB-induced senescence with special emphasis on the process of protein quality control. Copyright © 2017 Elsevier Inc. All rights reserved.

Three-dimensional multispectral optoacoustic mesoscopy reveals melanin and blood oxygenation in human skin in vivo.

PubMed

Schwarz, Mathias; Buehler, Andreas; Aguirre, Juan; Ntziachristos, Vasilis

2016-01-01

Optical imaging plays a major role in disease detection in dermatology. However, current optical methods are limited by lack of three-dimensional detection of pathophysiological parameters within skin. It was recently shown that single-wavelength optoacoustic (photoacoustic) mesoscopy resolves skin morphology, i.e. melanin and blood vessels within epidermis and dermis. In this work we employed illumination at multiple wavelengths for enabling three-dimensional multispectral optoacoustic mesoscopy (MSOM) of natural chromophores in human skin in vivo operating at 15-125 MHz. We employ a per-pulse tunable laser to inherently co-register spectral datasets, and reveal previously undisclosed insights of melanin, and blood oxygenation in human skin. We further reveal broadband absorption spectra of specific skin compartments. We discuss the potential of MSOM for label-free visualization of physiological biomarkers in skin in vivo. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Morphological and immunohistochemical reactions of the larval epidermis in the Italian newt (Lissotriton italicus) after exposure to low pH.

PubMed

Brunelli, Elvira

2018-02-01

Mounting evidence suggests that amphibians are globally and currently the most threatened group of vertebrates and different causes might be responsible for this phenomenon. Acidification of water bodies is a global environmental issue that has been proposed as a possible cause for amphibian populations decline. Indeed, it has been widely demonstrated that low pH may exert harmful effects on amphibians, either directly or by increasing the adverse effects of other stressors. Surprisingly only few studies documented the response of amphibian integument to acidic pH conditions and no data are available on the effects of a non-lethal level of pH onto the amphibian larval epidermis. The present study showed that acidic pH (4.5) condition has severe effects on the epidermis of the Italian newt (Lissotriton italicus, formerly Triturus italicus) inducing both morphological and functional alterations. The increase of mucus is the first evident effect of acid injury, followed by the flattening of the epithelium and the appearance of a keratinized shedding layer. The immunolabeling of cytokeratins substantially changes acquiring an adult-like pattern. Also aquaporin 3 and iNOS expression modify their distribution according to a change of the histological features of the epidermis. These results clearly indicate that a short-term exposure to a sub-lethal pH disrupts the epidermis morphology and function in L. italicus larvae. Since the skin exerts a prominent role in both respiration and osmoregulation, the described alterations may adversely affect the overall ionic balance, with a long chain of cascading effects significantly decreasing newts survival probabilities when environmental pH lowering occurs. Copyright © 2018 Elsevier GmbH. All rights reserved.

Anatomic Characteristics Associated with Head Splitting in Cabbage (Brassica oleracea var. capitata L.)

PubMed Central

Li, Xiaonan; Choi, Su Ryun; Wang, Yunbo; Sung, Chang-keun; Im, Subin; Ramchiary, Nirala; Zhou, Guangsheng; Lim, Yong Pyo

2015-01-01

Cabbage belonging to Brassicaceae family is one of the most important vegetables cultivated worldwide. The economically important part of cabbage crop is head, formed by leaves which may be of splitting and non-splitting types. Cabbage varieties showing head splitting causes huge loss to the farmers and therefore finding the molecular and structural basis of splitting types would be helpful to breeders. To determine which anatomical characteristics were related to head-splitting in cabbage, we analyzed two contrasting cabbage lines and their offspring using a field emission scanning electron microscope. The inbred line “747” is an early head-splitting type, while the inbred line “748” is a head-splitting-resistant type. The petiole cells of “747” seems to be larger than those of “748” at maturity; however, there was no significant difference in petiole cell size at both pre-heading and maturity stages. The lower epidermis cells of “747” were larger than those of “748” at the pre-heading and maturity stages. “747” had thinner epidermis cell wall than “748” at maturity stage, however, there was no difference of the epidermis cell wall thickness in the two lines at the pre-heading stage. The head-splitting plants in the F1 and F2 population inherited the larger cell size and thinner cell walls of epidermis cells in the petiole. In the petiole cell walls of “747” and the F1 and F2 plants that formed splitting heads, the cellulose microfibrils were loose and had separated from each other. These findings verified that anomalous cellulose microfibrils, larger cell size and thinner-walled epidermis cells are important genetic factors that make cabbage heads prone to splitting. PMID:26536356

The role of the integument as a barrier to penetration of ice into overwintering hatchlings of the painted turtle (Chrysemys picta).

PubMed

Willard, R; Packard, G C; Packard, M J; Tucker, J K

2000-11-01

Hatchlings of the North American painted turtle (Chrysemys picta) spend their first winter of life inside a shallow, subterranean hibernaculum (the natal nest) where they may be exposed for extended periods to ice and cold. Hatchlings seemingly survive exposure to such conditions by becoming supercooled (i.e., by remaining unfrozen at temperatures below the equilibrium freezing point for body fluids), so we investigated the role of their integument in preventing ice from penetrating into body compartments from surrounding soil. We first showed that hatchlings whose epidermis has been damaged are more likely to be penetrated by growing crystals of ice than are turtles whose cutaneous barrier is intact. We next studied integument from a forelimb by light microscopy and discovered that the basal part of the alpha-keratin layer of the epidermis contains a dense layer of lipid. Skin from the forelimb of other neonatal turtles lacks such a layer of lipid in the epidermis, and these other turtles also are highly susceptible to inoculative freezing. Moreover, epidermis from the neck of hatchling painted turtles lacks the lipid layer, and this region of the skin is readily penetrated by growing crystals of ice. We therefore conclude that the resistance to inoculation imposed by skin on the limbs of hatchling painted turtles results from the presence of lipids in the alpha-keratin layer of the epidermis. Neonates apparently are able to avoid freezing during winter by drawing much of the body inside the shell, leaving only the ice-resistant integument of the limbs exposed to ice in the environment. The combination of behavior and skin morphology enables overwintering hatchlings to exploit an adaptive strategy based on supercooling. Copyright 2000 Wiley-Liss, Inc.

The evolution of floral nectaries in Disa (Orchidaceae: Disinae): recapitulation or diversifying innovation?

PubMed

Hobbhahn, Nina; Johnson, Steven D; Bytebier, Benny; Yeung, Edward C; Harder, Lawrence D

2013-11-01

The Orchidaceae have a history of recurring convergent evolution in floral function as nectar production has evolved repeatedly from an ancestral nectarless state. However, orchids exhibit considerable diversity in nectary type, position and morphology, indicating that this convergence arose from alternative adaptive solutions. Using the genus Disa, this study asks whether repeated evolution of floral nectaries involved recapitulation of the same nectary type or diversifying innovation. Epidermis morphology of closely related nectar-producing and nectarless species is also compared in order to identify histological changes that accompanied the gain or loss of nectar production. The micromorphology of nectaries and positionally equivalent tissues in nectarless species was examined with light and scanning electron microscopy. This information was subjected to phylogenetic analyses to reconstruct nectary evolution and compare characteristics of nectar-producing and nectarless species. Two nectary types evolved in Disa. Nectar exudation by modified stomata in floral spurs evolved twice, whereas exudation by a secretory epidermis evolved six times in different perianth segments. The spur epidermis of nectarless species exhibited considerable micromorphological variation, including strongly textured surfaces and non-secreting stomata in some species. Epidermis morphology of nectar-producing species did not differ consistently from that of rewardless species at the magnifications used in this study, suggesting that transitions from rewardlessness to nectar production are not necessarily accompanied by visible morphological changes but only require sub-cellular modification. Independent nectary evolution in Disa involved both repeated recapitulation of secretory epidermis, which is present in the sister genus Brownleea, and innovation of stomatal nectaries. These contrasting nectary types and positional diversity within types imply weak genetic, developmental or physiological constraints in ancestral, nectarless Disa. Such functional convergence generated by morphologically diverse solutions probably also underlies the extensive diversity of nectary types and positions in the Orchidaceae.

Laser-induced transepidermal elimination of dermal content by fractional photothermolysis

NASA Astrophysics Data System (ADS)

Hantash, Basil M.; Bedi, Vikramaditya P.; Sudireddy, Vasanthi; Struck, Steven K.; Herron, G. Scott; Chan, Kin Foong

2006-07-01

The wound healing process in skin is studied in human subjects treated with fractional photothermolysis. In-vivo histological evaluation of vacuoles formed over microthermal zones (MTZs) and their content is undertaken. A 30-W, 1550-nm single-mode fiber laser system delivers an array of 60 µm or 140 µm 1/e2 incidence microbeam spot size at variable pulse energy and density. Treatments span from 6 to 20 mJ with skin excisions performed 1-day post-treatment. Staining with hematoxylin and eosin demonstrates an intact stratum corneum with vacuolar formation within the epidermis. The re-epithelialization process with repopulation of melanocytes and keratinocytes at the basal layer is apparent by 1-day post-treatment. The dermal-epidermal (DE) junction is weakened and separated just above zones of dermal coagulation. Complete loss of dermal cell viability is noted within the confines of the MTZs 1-day post-treatment, as assessed by lactate dehydrogenase. All cells falling outside the irradiation field remain viable. Content within the epidermal vacuoles stain positively with Gomori trichrome, suggesting a dermal origin. However, the positive staining could be due to loss of specificity after thermal alteration. Nevertheless, this dermal extrusion hypothesis is supported by very specific positive staining with an antihuman elastin antibody. Fractional photothermolysis creates microthermal lesions that allow transport and extrusion of dermal content through a compromised DE junction. Some dermal material is incorporated into the microepidermal necrotic debris and shuttled up the epidermis to eventually be exfoliated through the stratum corneum. This is the first report of a nonablative laser-induced transport mechanism by which dermal content can be predictably extruded biologically through the epidermis. Thus, treatment with the 1550-nm fiber laser may provide the first therapeutic option for clinical indications, including pigmentary disorders such as medically recalcitrant melasma, solar elastosis, as well as depositional diseases such as mucinosis and amyloidosis.

Synchrotron X-ray microfluorescence measurement of metal distributions in Phragmites australis root system in the Yangtze River intertidal zone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Huan; Zhang, Weiguo; Qian, Yu

2016-06-15

This study investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn inPhragmites australisroot system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X-ray microfluorescence, synchrotron transmission X-ray microscope measurement and synchrotron X-ray absorption near-edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils.Phragmites australissamples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that Fe nanoparticles are present in the root epidermis and thatmore » other metals correlate significantly with Fe, suggesting that Fe nanoparticles play an important role in metal scavenging in the epidermis.« less

[Morphology, anatomy and floral biology of Cabralea canjerana (Vell.) Mart. (Meliaceae)].

PubMed

Moscheta, Ismar S; de Souza, Luiz A; Mourão, Káthia S; da Rosa, Sônia M

2002-01-01

Cabralea canjerana (Vell.) Mart. is a tree that occurs frequently in secondary forests of Maringá, Paraná, Brazil and presents a valuable wood. Its flowering time occurs from August to October and the anthesis occurs during the night. Its flowers are visited by Lepidoptera-Noctuidae. The flowers are unisexual and solitary or arranged in panicles. The perianth presents a papillose epidermis with striate cuticle and a parenchymatic mesophyll. Ten stamens constitute the androecium and are arranged in a staminal tube with anthers. The anthers present epidermis, endothecium, two median layers and secretory tapetum with binucleate cells. The semi-inferior ovary presents anatropous, bitegmic and crassinucleate ovules. The nectaries are located in the base of the ovary and staminal tube and they present papillose epidermis with stomata and secretory parenchyma with a conspicuous phloematic tissue.

The expression and activation of protease-activated receptor-2 correlate with skin color.

PubMed

Babiarz-Magee, Laura; Chen, Nannan; Seiberg, Miri; Lin, Connie B

2004-06-01

Skin color results from the production and distribution of melanin in the epidermis. The protease-activated receptor-2 (PAR-2), expressed on keratinocytes but not on melanocytes, is involved in melanosome uptake via phagocytosis, and modulation of PAR-2 activation affects skin color. The pattern of melanosome distribution within the epidermis is skin color-dependent. In vitro, this distribution pattern is regulated by the ethnic origin of the keratinocytes, not the melanocytes. Therefore, we hypothesized that PAR-2 may play a role in the modulation of pigmentation in a skin type-dependent manner. We examined the expression of PAR-2 and its activator, trypsin, in human skins with different pigmentary levels. Here we show that PAR-2 and trypsin are expressed in higher levels, and are differentially localized in highly pigmented, relative to lightly pigmented skins. Moreover, highly pigmented skins exhibit an increase in PAR-2-specific protease cleavage ability. Microsphere phagocytosis was more efficient in keratinocytes from highly pigmented skins, and PAR-2 induced phagocytosis resulted in more efficient microsphere ingestion and more compacted microsphere organization in dark skin-derived keratinocytes. These results demonstrate that PAR-2 expression and activity correlate with skin color, suggesting the involvement of PAR-2 in ethnic skin color phenotypes.

Nonablative laser treatment of facial rhytides

NASA Astrophysics Data System (ADS)

Lask, Gary P.; Lee, Patrick K.; Seyfzadeh, Manouchehr; Nelson, J. Stuart; Milner, Thomas E.; Anvari, Bahman; Dave, Digant P.; Geronemus, Roy G.; Bernstein, Leonard J.; Mittelman, Harry; Ridener, Laurie A.; Coulson, Walter F.; Sand, Bruce; Baumgarder, Jon; Hennings, David R.; Menefee, Richard F.; Berry, Michael J.

1997-05-01

The purpose of this study is to evaluate the safety and effectiveness of the New Star Model 130 neodymium:yttrium aluminum garnet (Nd:YAG) laser system for nonablative laser treatment of facial rhytides (e.g., periorbital wrinkles). Facial rhytides are treated with 1.32 micrometer wavelength laser light delivered through a fiberoptic handpiece into a 5 mm diameter spot using three 300 microsecond duration pulses at 100 Hz pulse repetition frequency and pulse radiant exposures extending up to 12 J/cm2. Dynamic cooling is used to cool the epidermis selectively prior to laser treatment; animal histology experiments confirm that dynamic cooling combined with nonablative laser heating protects the epidermis and selectively injures the dermis. In the human clinical study, immediately post-treatment, treated sites exhibit mild erythema and, in a few cases, edema or small blisters. There are no long-term complications such as marked dyspigmentation and persistent erythema that are commonly observed following ablative laser skin resurfacing. Preliminary results indicate that the severity of facial rhytides has been reduced, but long-term follow-up examinations are needed to quantify the reduction. The mechanism of action of this nonablative laser treatment modality may involve dermal wound healing that leads to long- term synthesis of new collagen and extracellular matrix material.

Spontaneous Development of Cutaneous Squamous Cell Carcinoma in Mice with Cell-specific Deletion of Inhibitor of κB Kinase 2

PubMed Central

Kirkley, Kelly S; Walton, Kelly D; Duncan, Colleen; Tjalkens, Ronald B

2017-01-01

The deletion of NFκB in epithelial tissues by using skin-specific promoters can cause both tumor formation and severe inflammatory dermatitis, indicating that this signaling pathway is important for the maintenance of immune homeostasis in epithelial tissues. In the present study, we crossed mice transgenic for loxP-Ikbk2 and human Gfap-cre to selectively delete IKK2 in CNS astrocytes. Unexpectedly, a subset of mice developed severe and progressive skin lesions marked by hyperplasia, hyperkeratosis, dysplasia, inflammation, and neoplasia with a subset of lesions diagnosed as squamous cell carcinoma (SCC). The development of lesions was monitored over a 3.5-y period and over 4 filial generations. Average age of onset of was 4 mo of age with 19.5% of mice affected with frequency increasing in progressive generations. Lesion development appeared to correlate not only with unintended IKK2 deletion in GFAP expressing cells of the epidermis, but also with increased expression of TNF in lesioned skin. The skins changes described in these animals are similar to those in transgenic mice with an epidermis-specific deletion of NFκB and thus represents another genetic mouse model that can be used to study the role of NFκB signaling in regulating the development of SCC. PMID:28935002

Immunohistochemical evaluation of the heat shock response to nonablative fractional resurfacing

NASA Astrophysics Data System (ADS)

Hantash, Basil M.; Bedi, Vikramaditya P.; Struck, Steven K.; Chan, Kin F.

2010-11-01

Despite the emergence of nonablative fractional resurfacing (NFR) as a new therapeutic modality for skin photoaging, little is known about the molecular events that underlie the heat shock response to different treatment parameters. Human subjects are treated with a scanned 1550-nm fractional laser at pulse energies spanning 6 to 40 mJ and a 140-μm spot size. The heat shock response is assessed immunohistochemically immediately through 7 days posttreatment. At the immediately posttreatment time point, we observe subepidermal clefting in most sections. The basal epidermis and dermal zones of sparing are both found to express HSP47, but not HSP72. By day 1, expression of HSP72 is detected throughout the epidermis, while that of HSP47 remains restricted to the basal layer. Both proteins are detected surrounding the dermal portion of the microscopic treatment zone (MTZ). This pattern of expression persists through day 7 post-NFR, although neither protein is found within the MTZ. Immediately posttreatment, the mean collagen denaturation zone width is 50 μm at 6 mJ, increasing to 202 μm at 40 mJ. The zone of cell death exceeds the denaturation zone by 19 to 55% over this pulse energy range. The two zones converge by day 7 posttreatment.

Mutations in gasdermin 3 cause aberrant differentiation of the hair follicle and sebaceous gland.

PubMed

Lunny, Declan P; Weed, Erica; Nolan, Patrick M; Marquardt, Andreas; Augustin, Martin; Porter, Rebecca M

2005-03-01

Defolliculated (Dfl) is a spontaneous mouse mutant with a hair-loss phenotype that includes altered sebaceous gland differentiation, short hair shafts, aberrant catagen stage of the hair cycle, and eventual loss of the hair follicle. Recently a similar mutant, finnegan (Fgn), with an identical phenotype was discovered during a phenotypic screen for mutations induced by chemical mutagenesis. The gene underlying the phenotype of both finnegan and defolliculated has been mapped to chromosome 11 and here we show that both mice harbor mutations in gasdermin 3 (Gsdm3), a gene of unknown function. Gsdm3(Dfl) is a B2 insertion near the 3' splice site of exon 7 and Gsdm3(Fgn) is a point mutation T278P. To investigate the role of the gasdermin gene family an antiserum was raised to a peptide highly homologous to all three mouse gasdermins and human gasdermin. Immunohistochemical analysis revealed that gasdermins are expressed specifically in cells at advanced stages of differentiation in the upper epidermis, the differentiating inner root sheath and hair shaft and in the most mature sebocytes of the sebaceous gland and preputial, meibomium, ceruminous gland, and anal glands. This expression pattern suggests a role for gasdermins in differentiation of the epidermis and its appendages.

Rotation is the primary motion of paired human epidermal keratinocytes.

PubMed

Tate, Sota; Imai, Matome; Matsushita, Natsuki; Nishimura, Emi K; Higashiyama, Shigeki; Nanba, Daisuke

2015-09-01

Collective motion of keratinocytes is involved in morphogenesis, homeostasis, and wound healing of the epidermis. Yet how the collective motion of keratinocytes emerges from the behavior of individual cells is still largely unknown. The aim of this study was to find the cellular behavior that links single and collective motion of keratinocytes. We investigated the behavior of two-cell colonies of HaCaT keratinocytes by a combination of time-lapse imaging and image processing. The two-cell colonies of HaCaT cells were formed as a contacted pair of keratinocyte clones. Image analysis and cell culture experiments revealed that the rotational speed of two-cell colonies was positively associated with their proliferative capacity. α6 integrin was required for the rotational motion of two-cell keratinocyte colonies. We also confirmed that two-cell colonies of keratinocytes predominantly exhibited the rotational, but not translational, motion, two modes of motion in a contact pair of rotating objects. The rotational motion is the primary motion of two-cell keratinocyte colonies and its speed is positively associated with their proliferative capacity. This study suggests that the assembly of rotating keratinocytes generates the collective motion of proliferative keratinocytes during morphogenesis and wound healing of the epidermis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.